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c     File:     geom_base
c
c     Author:   Arthur L. Edwards (email:  <edwards5@llnl.gov>, <xenops@comcast.net>)
c
c     Version:  Updated    2007 May 30 15:00.
c               Originated 1993 September 8 16:00.
c
c     Source:   Web site http://nuclear.llnl.gov/CNP/apt/.
c
c     Purpose:  File geom_base is a database for the GEOM code, which does a
c               variety of geometric, Monte Carlo, mathematical and data
c               manipulation operations, including 3-D ray tracing (geometric
c               optics) and particle tracking, and may be used to test and to
c               demonstrate the use of many subroutines in the APT Subroutine
c               Library.
c
c               The GEOM code is an interactive code with its own command
c               language, including the use of subscripted variables and the
c               equivalents of do loops, if-endif blocks, and subroutine calls.
c
c               File geom_base is in the form of a thoroughly cross-referenced
c               alphabetically organized encylopedia, with the following format:
c
c               Between entries:
c                 Columns  1-80:  Blank.
c               The first line of entries:
c                 Columns  1- 5:  A flag, indicating the type of entry.
c                 Columns  6- 6:  Blank.
c                 Columns  7-24:  The entry name, if < 20 characters.
c                 Columns  7-80:  The entry name, if > 19 characters.
c                 Columns 25-25:  Blank, if the entry name has < 20 characters.
c                 Columns 26-80:  Beginning of the entry body, containing a
c                                 description or definition of the entry name,
c                                 and sometimes commands related to the entry,
c                                 if the entry name has < 20 characters.
c               Additional lines of entries:
c                 Columns 28-80:  The rest of the entry body.
c
c               To find an entry, e.g. ENTRY, in this file using a general
c               search tool, specify the entry as "cc    ENTRY" for commands,
c               or "cg    ENTRY" for other definitions or descriptions.
c               See "search geom_base".
c
c               To extract entries that contain any desired key words, see
c               "extract entries".
c
c               File geom_defs contains an alphabetical list of all entries
c               in geom_base.
c
c               To execute GEOM, see "GEOM execution".
c
c               To display entries in this file during execution of GEOM, see
c               command "define".
c
c     Note:     In command lines, arguments shown in lower case are to be typed
c               literally as shown.  Arguments shown in UPPER CASE are place
c               holders, indicating data to be provided by the user, unless
c               otherwise stated.  Arguments in square brackets are options with
c               choices and/or defaults.  See entry "[".
c
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc

FLAG  ENTRY              DESCRIPTION OR DEFINITION

!-@-----------------------------------------------------------------------------

cc    !                  The exclamation point (or "bang").  The first character
cc                         of a comment line, or following a field delimiter in
cc                         a command line, the beginning of an appended comment.
cc
cc                         Ignored in command "hex".
cc
cc                         The character ";", if not bracketed by single or
cc                         double quotes, will terminate a comment, allowing a
cc                         command to follow on the same line.
cc
cc                         Do not use the character "!" at the beginning of the
cc                         name of any alias, marker, symbol or other object.
cc
cc                         See "c", "#", "*", "/".

cg    !                  In a mathematical expression, following a non-negative
cg                         integer, indicates the factorial function:
cg                         0! = 0, 1! = 1, N! = 1 * 2 * ... * (N - 1) * N.

cc    "                  In command "alias", delimits the replacement string.
cc                         Double any " in the replacement string.
cc                         Synonyms:  [", ' (in pairs)].

cc    "                  In command "define", delimits the entry.
cc                         Double any " in the entry.
cc                         Synonyms:  [", ' (in pairs)].

cc    "                  In command "marker", delimits the text string.
cc                         Double any " in the text string.
cc                         Synonyms:  [", ' (in pairs)].

cc    #                  If the first character of an input line, the entire
cc                         input line is treated as a comment, and echoed in the
cc                         output file.  See "c".
cc                         Synonyms:  [#, *, /].

cc    #                  The first character of a comment line.
cc                         Synonyms:  [#, *, /].
cc                         See "c", "!".

cc    #                  An option in command "input", to switch input to the
cc                         previous input medium, starting with the line after
cc                         the last line read from that input medium, and with
cc                         the same specification for the final line to be read.
cc                         See "%", command "return".

cc    $                  An option in command "input", in place of LINE1 or
cc                         LINE2, to indicate the last line saved in memory,
cc                         or the end-of-file of an input file.

cc    $                  An option in commands "indo" and "redo", in place of
cc                         LINE, to indicate the last line saved in memory.

cc    $                  May be used as the first character of a variable name,
cc                         as may "@", "%" or any lower case letter, or any
cc                         upper case letter followed by one or more characters.

cg    %                  In a display of data resulting from command "mcvol",
cg                         percent, as in "% estimated error".

cc    %                  An option in command "input", to indicate the current
cc                         input file, when used in place of IN_FILE.  Used to
cc                         move to a different line in the current input file.

cc    %                  May be used as the first character of a variable name,
cc                         as may "@", "$" or any lower case letter, or any
cc                         upper case letter followed by one or more characters.

cc    &                  An option in command "cluster", to indicate that
cc                         additional points are being added to an existing
cc                         cluster.
cc                         To add additional clusters to an existing cluster,
cc                         use command "cluster CLNAME cluster CLNAME ...".

cc    &                  An option in command "pdf", to indicate that
cc                         additional probability bins are being specified for
cc                         a pdf already partially specified.

cc    &                  An option in command "quadric", to respecify one or
cc                         more individual coefficients in the general implicit
cc                         equation of a specified quadric surface.  Options
cc                         CFNAME1, CFNAME2, ... may be QC, QX, QY, QZ, QXY,
cc                         QYZ, QZX, QXX, QYY or QZZ.

cc    &                  An option in command "zone", to indicate that
cc                         additional bounding surfaces are being specified for
cc                         a zone already partially specified.

cc    '                  A synonym for ", in commands "alias", "define",
cc                         "marker" and "variable".

cc    '                  In command "alias", delimits the replacement string.
cc                         Double any ' in the replacement string.
cc                         Synonyms:  [", ' (in pairs)].

cc    '                  In command "define", delimits the entry.
cc                         Double any ' in the entry.
cc                         Synonyms:  [", ' (in pairs)].

cc    '                  In command "marker", delimits the text string.
cc                         Double any ' in the text string.
cc                         Synonyms:  [", ' (in pairs)].

cg    (, )               The parenthesis characters.  See "subscripts".

cg    (xyz)              In a display of data, indicates three coordinates of a
cg                         point or three components of a vector, in Cartesian
cg                         (x, y, z) coordinates.  To convert to another
cg                         coordinate system, use the following commands:
cg
cg                         coordinate xyz
cg                         [point,vector] TEMP = {copy xyz coordinates here}
cg                         coordinate [cyl,sph]
cg                         angle [deg,rad]
cg                         [point,vector] TEMP
cg
cg                         See "cut and paste", "coordinate conversion",
cg                         "vector conversion".

cc    *                  A synonym for # in a comment line.

cc    *                  An option in commands "big", "icalc" and "variable",
cc                         argument FUNCTION, to indicate multiplication.
cc                         In the expression A * B, indicates that A is
cc                         multiplied by B.

cc    *                  An option in command "quadric", to indicate that the
cc                         coefficients of the implicit equation of the quadric
cc                         surface are to be multiplied by argument FACT.

cc    *                  An option in command "variable VARNEW = K * L mod M",
cc                         to multiply K by L.

cc    *                  An option in command "variable", to give the variable
cc                         the value of the product of the specified arguments.

cc    *                  A synonym for rel in command "vector".

cc    *                  An option in command "variable VARNEW = K * L mod M",
cc                         to multiply K by L.

cc    **                 A synonym for ^.

cc    +                  When used as a prefix (without a delimiter) to a
cc                         variable name used in place of an integer or floating
cc                         point argument, has no effect.  See "-".

cc    +                  In a command that creates, copies or renames an object,
cc                         a "+" in place of the object name indicates that the
cc                         object name should be formed by incrementing the base
cc                         name for the object type.  The base name is the name
cc                         of the last object of that type created, or the base
cc                         name specified with command "last", whichever occurs
cc                         later.
cc                         The new name becomes the current base name.
cc                         The "+" option may not be used in command "delete",
cc                         or in command "rename" with option "array".
cc                         See command "last", "increment names", "-".
cc
cc                         You must be sure that incrementing a base name
cc                         does not create a disallowed name, that could be
cc                         interpreted as a key word in a command, such as
cc                         "all", "comp.", "h", "help", "list", "random",
cc                         "thru" or "?".

cc    +                  An option in commands "big", "icalc" and "variable",
cc                         argument FUNCTION, to indicate addition.  In the
cc                         expression x + y, indicates that y is added to x.

cc    +                  An option in commands "invert", "reflect", "rotate" or
cc                         "scale".  The delimited character "+" preceding the
cc                         name of a tensor operator indicates that the
cc                         specified tensor operator will be used (the default
cc                         option), rather than its inverse.
cc                         The word "+" is the default option, and need not be
cc                         included in the command.

cc    +                  An option in command "sort", to sort in increasing
cc                         alphanumeric order.  The default option.

cc    +                  An option in command "variable", to give the variable
cc                         the value of the sum of the specified arguments.

cc    +                  An option in command "variable VARNEW = K + L mod M",
cc                         to add L to K.

cc    +                  An option in command "zone".  The delimited character
cc                         "+" preceding the name of a bounding surface
cc                         indicates that the direction out of the zone is in
cc                         the same direction as the normal vector of the
cc                         bounding surface.
cc                         If not specified, the default argument is "+".
cc
cc                         For example, if the zone is inside of a sphere,
cc                         cylinder, cone or ellipsoid that has been created
cc                         by any command other that "quadric QNAME = ...",
cc                         the corresponding argument is blank or "+".

cc    ,                  In subscripted object names, used to separate
cc                         subscripts from each other.

cg    -                  See "- |...|".

cg    -                  When the first character of a point name, indicates the
cg                         point was previously a mesh point, and was released
cg                         from the mesh.  A point with a name beginning with
cg                         a minus sign may not be assigned to the mesh.

cc    -                  When used as a prefix (without a delimiter) to a
cc                         variable name used in place of an integer or floating
cc                         point argument, results in use of the negative of the
cc                         variable value.  See "+".

cc    -                  In a command that creates, copies or renames an object,
cc                         a "-" in place of the object name indicates that the
cc                         object name should be formed by decrementing the base
cc                         name for the object type.  The base name is the name
cc                         of the last object of that type created, or the base
cc                         name specified with command "last", whichever occurs
cc                         later.  The new name becomes the current base name.
cc                         The "-" option may not be used in command "delete",
cc                         or in command "rename" with option "array".
cc                         See command "last", "increment names", "-".
cc
cc                         You must be sure that decrementing a base name
cc                         does not create a disallowed name, that could be
cc                         interpreted as a key word in a command, such as
cc                         "all", "comp.", "h", "help", "list", "random",
cc                         "thru" or "?".

cc    -                  An option in command "cluster", to remove points from
cc                         an existing cluster, either by point names or by
cc                         the names of clusters containing the points.

cc    -                  An option in commands "big", "icalc" and "variable",
cc                         argument FUNCTION, to indicate subtraction.  In the
cc                         expression x - y, indicates that y is subtracted
cc                         from x.

cc    -                  An option in commands "mesh" and "point", to release
cc                         the assignment of mesh indices to mesh points
cc                         (make the mesh indices zero).

cc    -                  An option in command "pdf", to remove probability bins
cc                         from an existing pdf.

cc    -                  An option in command "plot center", to default the
cc                         plot center to the center of the plot axes.
cc                         An option in command "plot limits", to specify that
cc                         the plot axis limits will include all plot points.

cc    -                  An option in command "rotate".  The delimited character
cc                         "-" preceding the name of a rotation operator,
cc                         indicates that the inverse of the specified rotation
cc                         operator will be used.
cc                         Do not use this option in commands "invert" or
cc                         "reflect".

cc    -                  An option in command "sort", to sort in decreasing
cc                         alphanumeric order.

cc    -                  An option in command "zone".  The delimited character
cc                         "-" preceding the name of a bounding surface
cc                         indicates that the direction out of the zone is in
cc                         the opposite direction of the normal vector of the
cc                         bounding surface.
cc                         If not specified, the default argument is "+".
cc
cc                         For example, if the zone is outside of a sphere,
cc                         cylinder, cone or ellipsoid that has been created
cc                         by any command other that "quadric QNAME = ...",
cc                         the corresponding argument is "-".

cc    -                  An option in command "brick", option "increment".
cc                         The delimited character "-" preceding the name of a
cc                         coordinate direction indicates that bricks are to be
cc                         created in the negative coordinate direction from a
cc                         base brick.

cc    -                  An option in command "variable VARNEW = K - L mod M",
cc                         to subtract L from K.

cg    - |...|            Indicates that the quantity bracketed by "|" characters
cg                         must be negative.

cg    -999999999         Sometimes used for a value when no correct value can
cg                         be found.

cg    .                  See ". (period)".

cc    . (period)         A synonym for 0, in command indo.

cc    . (period)         An option in command "redo".  When used for R1, R2, R3,
cc                         ..., means to use the original argument, with no
cc                         replacement.

cc    . (period)         Command to repeat the preceding command.
cc                         Do not use the statement separator ";" on the same
cc                         line following this command.
cc
cc                         Forms include:
cc
ccin                       . help
cc
cc                           Display the command options.
cc
ccin                       .
cc
cc                           Repeat the preceding command.
cc                           This is the same as the command "input command -1".
cc                           To repeat the preceding N commands, use command
cc                           "input command -N $".
cc
cc                         Synonyms:  [help, h].

cc    .and.              An option in command 'icalc", to find the Boolean
cc                         "and" or "intersection" of two machine words.
cc                         M .and. N means the Boolean "and" or "intersection"
cc                         of M and N.
cc                         Use 1 where M and N have a 1, otherwise 0.
cc                         See "Boolean".
cc                         Synonyms:  [.and., .int.].

cc    .and.              An option in command "cluster", to create a cluster
cc                         consisting of all points that are in both of two
cc                         specified clusters.  This is the Boolean "and" or
cc                         "intersection" of the two specified clusters.

cc    .eq.               A synonym for = in command "if".

cc    .eqv.              A synonym for .xnor. in commands "cluster" and "icalc".

cn    .exrc              A VI command file, for use when reading or editing this
cn                         file with UNIX text editor VI.  Allows a search for
cn                         a pattern starting in column 7 by beginning the VI
cn                         command with "q", followed by the pattern.

cc    .ge.               A synonym for >= in command "if".

cc    .gt.               A synonym for > in command "if".

cc    .int.              A synonym for .and. in commands "cluster" and "icalc".

cc    .le.               A synonym for <= in command "if".

cc    .lt.               A synonym for < in command "if".

cc    .nand.             A Boolean operation.  In the case of two binary digits,
cc                         returns a 0 if both are 1, otherwise returns a 1.

cc    .nand.             An option in command "icalc", to find the Boolean
cc                         "nand" of two machine words.
cc                         M .nand. N means the Boolean "nand" of M and N
cc                         (0 where both M and N have a 1-bit, otherwise 1).
cc                         See "Boolean".

cc    .nand.             An option in command "cluster", to create a cluster
cc                         consisting of all points that are not in both of
cc                         two specified clusters.  This is the Boolean "nand"
cc                         of the two specified clusters.

cc    .ne.               A synonym for /= in command "if".

cc    .nor.              A Boolean operation.  In the case of two binary digits,
cc                         returns a 1 if both are zero, otherwise returns zero.

cc    .nor.              An option in command "icalc", to find the Boolean
cc                         "nor" of two machine words.
cc                         M .nor. N means the Boolean "nor" of M and N
cc                         (1 where both M and N have a 0-bit).  See "Boolean".

cc    .nor.              An option in command "cluster", to create a cluster
cc                         consisting of all points that are in neither of
cc                         two specified clusters.  This is the Boolean "nor"
cc                         of the two specified clusters.

cc    .not.              A Boolean operation.  In the case of two binary digits,
cc                         returns a 1 if the first is 1 and the second is 0,
cc                         otherwise returns zero.

cc    .not.              An option in command "icalc", to find the Boolean
cc                         "not" of two machine words.
cc                         M .not. N means the Boolean "not" of M and N
cc                         (1 where M has a 1-bit and N has a 0-bit).
cc                         See "Boolean".

cc    .not.              An option in command "cluster", to create a cluster
cc                         consisting of all points in one specified cluster
cc                         but not in another specified cluster.

cc    .or.               An option in command 'icalc", to find the Boolean
cc                         union of two machine words.
cc                         M .or. N means the Boolean "or" or "union" of M and N
cc                         (1 where either M or N has a 1-bit).  See "Boolean".
cc                         Synonyms:  [.or., .un.].

cc    .or.               An option in command "cluster", to create a cluster
cc                         consisting of all points that are in either of
cc                         two specified clusters.  This is the Boolean
cc                         "or" or "union" of the two specified clusters.

cc    .un.               A synonym for .or. in commands "cluster" and "icalc".

cc    .xnor.             A Boolean operation.  In the case of two binary digits,
cc                         returns a 1 if both are 0 or both are 1.

cc    .xnor.             An option in command 'icalc", to find the Boolean
cc                         "xnor" of two machine words.
cc                         M .xnor. N means the Boolean "xnor" of M and N
cc                         (1 where both M and N have a 1-bit, or both M and N
cc                         have a 0-bit).  See "Boolean".

cc    .xnor.             An option in command "cluster", to create a cluster
cc                         consisting of all points which are in either both
cc                         or neither of two specified clusters.  This is the
cc                         Boolean "equivalence" of the two specified clusters.
cc                         Synonymns:  [.xnor., .eqv.].

cc    .xor.              An option in command 'icalc", to find the Boolean
cc                         exclusive or of two machine words.
cc                         M int N means the Boolean exclusive or of M and N.
cc                         See "Boolean".

cc    .xor.              An option in command "cluster", to create a cluster
cc                         consisting of all points that are in one, but not
cc                         the other, of two specified clusters.  This is the
cc                         Boolean "exclusive or" of the two specified clusters.

cc    /                  An option in commands "big", "icalc" and "variable",
cc                         argument FUNCTION, to indicate division.  In the
cc                         expression x / y, indicates that x is divided by y.

cc    /                  An option in command "quadric", to indicate that the
cc                         coefficients of the implicit equation of the quadric
cc                         surface are to be divided by argument FACT.

cc    /                  A synonym for # in a comment line.

cc    /                  An option in commands "icalc" and "variable".  When
cc                         used for FUNCTION, indicates division of the
cc                         preceding argument by the following argument.

cc    /                  An option in command "variable", to give the variable
cc                         the value of the sum of the reciprocals of the
cc                         specified arguments.

cc    /                  An option in command "variable VARNEW = K / L mod M",
cc                         to multiply K by the multiplicative inverse of L, if
cc                         it exists.

cc    /=                 An option in command "if", meaning not equal to.
cc                         Synonyms:  [/=, =/, .ne.].

cc    //                 An option in command "big", to divide one big integer
cc                         by another big integer as many times as possible, if
cc                         an exact factor.

cg    /^......STRING     A VI command to search for a character string STRING
cg                         which starts in column 7 of this file.

cc    0                  An option in command "indo".  When used for I1, I2, I3,
cc                         ..., means to use the original argument, with no
cc                         increment.
cc                         Synonyms:  [0, .].

cg    10^(-99)           Sometimes used for a value when no correct value can be
cg                         found.

cg    10^99              Sometimes used for a value when no correct value can be
cg                         found.  As an input argument, specified as "1E99".

cc    17777777777        In command "icalc", the largest allowed octal
cc                         integer on a 32-bit computer.
cc                         Same as 2147483647 decimal, 7fffffff hex.

cg    21                 A game (blackjack) which may be played with GEOM,
cg                         using input file 21.mac.

cc    2147483647         In command "icalc", the largest allowed decimal
cc                         integer on a 32-bit computer.
cc                         Same as 17777777777 decimal, 7fffffff hex.

cc    777777777777777777777
cc                         In command "icalc", the largest allowed octal
cc                         integer on a 64-bit computer.
cc                         Same as 9223372036854775807 decimal,
cc                         7FFFFFFFFFFFFFFF hex.

cc    7fffffff           In command "icalc", the largest allowed hexadecimal
cc                         integer on a 32-bit computer.
cc                         Same as 2147483647 decimal, 17777777777 octal.

cc    7fffffffffffffff   In command "icalc", the largest allowed hexadecimal
cc                         integer on a 64-bit computer.
cc                         Same as 9223372036854775807 decimal,
cc                         777777777777777777777 oct.

cc    80                 Maximum number of characters read in an input line,
cc                         including input lines expanded by substitution of
cc                         an alias.

cc    9223372036854775807
cc                         In command "icalc", the largest allowed decimal
cc                         integer on a 64-bit computer.
cc                         Same as 777777777777777777777 octal,
cc                         7FFFFFFFFFFFFFFF hex.

cc    ;                  Separates multiple commands and/or comments on one
cc                         input line.  Ignored if between single or double
cc                         quotes (as in commands "alias", "define" and
cc                         "marker").  Does not need to be delimited.
cc                         If not between single or double quotes, will
cc                         terminate a comment, allowing a command to follow on
cc                         the same line.  Ignored in command "hex".
cc                         For example:
cc
ccin                       COMMAND1;COMMAND2 !COMMENT;COMMAND3 ...
cc
cc                           Execute commands COMMAND1, COMMAND2, COMMAND3, ...
cc
cc                         Can not be used after commands "do", "enddo",
cc                         "indo", "input", "read", "redo", "return" or"undo",
cc                         or their synonyms, because chaos might ensue.
cc
cc                         WARNING:  if used in an input file, the line number
cc                         displayed in the output file will not be the same
cc                         as in the input file, but will be a statement
cc                         counter, instead.  To reexecute lines, use command
cc                         "input geom_cmd ?" to find the correct line numbers
cc                         to use, say N1 through N2, and then use command
cc                         "input geom_cmd N1 N2" to execute them.

cc    <                  An option in command "if", meaning less than.
cc                         Synonyms:  [<, .lt.].

cc    <                  Used in a UNIX execution line to redirect the standard
cc                         input.  Do NOT use any of the GEOM execution lines:
cc                         "geom < IN_FILE"           ,
cc                         "geom < IN_FILE > OUT_FILE",
cc                         "geom   IN_FILE > OUT_FILE" or
cc                         "geom           > OUT_FILE".
cc
cc                         The following forms are allowed, to prevent large
cc                         amoumts of data from being displayed on the user's
cc                         terminal:
cc
cc                         "geom   IN_FILE   OUT_FILE  >   STDOUT"
cc                         "geom   IN_FILE   OUT_FILE  >!  STDOUT"
cc
cc                         The latter form allows writing over an existing
cc                         file STDOUT.
cc
cc                         See "GEOM execution".

cg    <                  In column 1 of the output file, indicates an input
cg                         line that begins with "input", "read", "return",
cg                         "call", "goto", "undo", "redo", "indo" or a synonym
cg                         for any of these, or an alias.  See ">".

cc    <=                 An option in command "if", meaning less than or
cc                         equal to.  Also in displayed values from command
cc                         "root".
cc                         Synonyms:  [<=, =<, .le.].

cc    <return>           The <return> key must be typed at the end of every
cc                         input line typed at the user's terminal.

cc    =                  An option in some commands that create objects, between
cc                         the object name and the specification of the object.

cc    =                  An option in command "if", meaning equal to.
cc                         Synonyms:  [=, .eq.].

cc    =                  An option in command "root", to find the real
cc                         coefficients of an Nth-order polynomial equation
cc                         with N specified real roots.

cc    =                  An option in command "roots", to find the real
cc                         coefficients of a polynomial equation with from
cc                         one to four specified real and/or complex roots.

cc    =/                 A synonym for /= in command "if".

cc    =<                 A synonym for <= in command "if".

cc    =>                 A synonym for >= in command "if".

cc    >                  An option in command "if", meaning greater than.
cc                         Synonyms:  [>, .gt.].

cg    >                  In column 1 of the output file, indicates an input
cg                         line that does not begin with "input", "read",
cg                         "return", "undo", "redo", "indo" or a synonym for
cg                         any of these, or an alias.  A new input file, which
cg                         will duplicate the run that made the output file, may
cg                         be made by selecting only those lines beginning with
cg                         ">" from the input file, then deleting the ">".
cg                         See "<".

cc    >                  Used in a UNIX execution line to redirect the standard
cc                         output.  Do NOT use any of the GEOM execution lines:
cc                         "geom < IN_FILE"           ,
cc                         "geom < IN_FILE > OUT_FILE",
cc                         "geom   IN_FILE > OUT_FILE" or
cc                         "geom           > OUT_FILE".
cc
cc                         See "GEOM execution".

cc    >=                 An option in command "if", meaning greater than or
cc                         equal to.
cc                         Synonyms:  [>=, =>, .ge.].

cc    ?                  The default short input prompt, if the long prompt is
cc                         turned off.  Input may follow this prompt on the
cc                         same line.

cc    ?                  A synonym for random, except in command "input".

cc    ?                  An option in command "input", to indicate that the
cc                         contents of the specified file will be displayed
cc                         by the standard output (normally the user's
cc                         terminal) and in the output file, preceded by line
cc                         numbers, but not executed.  Is not a synonym for
c                          random in command "input".

cc    ?                  An option in command "sort", to sort in random
cc                         alphanumeric order.

cc    @                  May be used as the first character of a variable name,
cc                         as may "$", "%" or any lower case letter, or any
cc                         upper case letter followed by one or more characters.

cg    A                  The frequency of the musical note Concert A, or A4,
cg                         is 440 Hz.  Middle C (C4) is 523.2511306012 Hz.

A-------------------------------------------------------------------------------

cc    a                  A synonym for add, when responding to question about
cc                         appending to an existing output file.

cc    a                  A synonym for alias.

cc    A(N)               In command "variable", option "polynomial", the
cc                         coefficient of XARG^N in a polynomial function of
cc                         XARG.  N = 0 to whatever will fit on the command
cc                         line.  See command "roots", option "?".


cc    A(n)               In command "root", the coefficient of x^n in the
cc                         polynomial P(x) = sum(n=1,N) {A(n) * x^n} = 0.

cc    A0                 In command "roots", the constant term in the polynomial
cc                         equation to be solved.
cc                         If A0 is zero, at least one root is zero.

cc    A1                 In command "roots", the coefficient of z in the
cc                         quadratic, cubic or quartic polynomial equation to be
cc                         solved.  If A0 and A1 are zero, at least two roots
cc                         are zero.

cc    A2                 In command "roots", the coefficient of z^2 in the
cc                         quadratic, cubic or quartic polynomial equation to be
cc                         solved.  If A0 = A1 = A2 = 0, at least three roots
cc                         are zero.

cc    A3                 In command "roots", the coefficient of z^3 in the
cc                         cubic or quartic polynomial equation to be solved.
cc                         If A0 = A1 = A2 = A3 = 0, at least four roots
cc                         are zero.

cc    A4                 In command "roots", the coefficient of z^4 in the
cc                         quartic polynomial equation to be solved.

cc    abs                An option in command "variable", argument FUNCTION,
cc                         to indicate the absolute value function.
cc                         A abs B means A * abs (B).

cc    abs                An option in command "vector", to give the vector an
cc                         absolute length equal to ABSLEN (defaults to 1).
cc                         See "ABSLEN", "rel", "relative".

cf    abs                The absolute value function.  Example:  y = abs (x)
cf                         means y is positive, with the magnitude of x.

cc    ABSLEN             Length of a vector of type "absolute".  Defaults to 1.
cc                         May be integer, floating point or a variable.
cc                         Specified with command "vector".

cg    absolute           A vector specified by two points is absolute if key
cg                         word "rel" or "*" is not used.  If key word "abs" or
cg                         "unit" is used, the vector will have a length equal
cg                         to ABSLEN (defaults to 1).
cg                         Once a vector has been created, it no longer depends
cg                         on any points used to create it.
cg                         See "ABSLEN", "rel", "relative", "vector".

cc    accel              A synonym for accelerate.

cc    accelerate         Command to find the position, path length and velocity
cc                         on the parabolic trajectory of a particle with a
cc                         specified initial position, initial velocity and
cc                         constant acceleration, for a specified range of
cc                         times or at specified time intervals,
cc                         or to find the intersection of the particle path with
cc                         one or more points, a line, a plane or a quadric
cc                         surface, or to find the initial position and velocity
cc                         and constant acceleration for a particle, given two
cc                         or three positions at two or three times.
cc
cc                         Command "accelerate" relates to objects:  axisym,
cc                         cluster, cone, cylinder, ellipsoid, hyperb, line,
cc                         plane, point, quadric, sphere, symbol, variable,
cc                         vector.
cc
cc                         Forms include:
cc
ccin                       help accelerate
ccin                       accelerate [help]
cc
cc                           Display the command options.
cc
ccin                       accelerate path PINIT VINIT VACC
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type
cc                           (simple linear, degenerate linear parabolic or
cc                           parabolic), and if parabolic, find the position,
cc                           path length and velocity at the vertex of its path.
cc
ccin                       accelerate path PINIT VINIT VACC time TMIN [DT TMAX]
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and the position, path length
cc                           and velocity, for time[s] TMIN [(DT) TMAX].
cc                           Any unspecified words at the end of the command,
cc                           after TMIN, default to 0.
cc
ccin                       accelerate path PINIT VINIT VACC point PNAME
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and the points on its path
cc                           that intersect or are proximal to the point PNAME,
cc                           and for each such point, the coordinates, the
cc                           velocity, the path length, the time, and the
cc                           distance to point PNAME.
cc                           If point PNAME is not on the path, find any initial
cc                           velocities VINIT' with the same magnitude as VINIT,
cc                           that will make the path intersect point PNAME.
cc
ccin                       accelerate path PINIT VINIT VACC cluster CLNAME
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and the other data as in the
cc                           preceding command, for each point in cluster
cc                           CLNAME.
cc
ccin                       accelerate path PINIT VINIT VACC line ALNAME
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and the points on its path
cc                           that intersect or are proximal to the line ALNAME,
cc                           and for each such point, the coordinates, the
cc                           velocity, the path length, the time, and the
cc                           distance to line ALNAME.
cc
ccin                       accelerate path PINIT VINIT VACC plane PLNAME
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and the points on its path
cc                           that intersect or are proximal to the plane PLNAME,
cc                           and for each such point, the coordinates, the
cc                           velocity, the path length and the time.  For a
cc                           proximal point, find the proximal point on the
cc                           plane, and the distance from the plane to the
cc                           particle.
cc
ccin                       accelerate path PINIT VINIT VACC quadric QNAME
cc
cc                           For a particle initially at point PINIT, with
cc                           initial velocity vector VINIT and constant
cc                           acceleration vector VACC, find the path type and
cc                           vertex data as above, and any points on its path
cc                           that intersect the quadric surface QNAME, and for
cc                           each such point, the coordinates, the velocity, the
cc                           path length and the time.  To check the results,
cc                           store each such intersection point in PNAME, and
cc                           use command "side PNAME QNAME".
cc                           If no intersection points are found, find any
cc                           extrema of the quadric surface equation on the
cc                           particle path.  In general, these are NOT proximal
cc                           or distal points, but may be used as initial
cc                           guesses in finding such points.
cc
ccin                       accelerate fit P1 [T1 P2 T2 [P3 T3]]
cc
cc                           For a particle at from one to three points and
cc                           times P1 and T1, P2 and T2, and P3 and T3, find the
cc                           position and velocity at time zero, and the
cc                           constant acceleration vector for a parabolic
cc                           trajectory.  Each time specified must be different.
cc                           If all points are the same, the velocity and
cc                           acceleration will be zero.  If only two points are
cc                           specified, the acceleration will be zero.  If any
cc                           two of three specified points are the same, the
cc                           acceleration will be parallel to the velocity.
cc                           If three specified points are collinear, the
cc                           acceleration will be parallel to the velocity.
cc
cc                         Synonyms:  [accelerate, accel], [help, h],
cc                         [plane, pl], [quadric, q, quad], [time, t].

cg    acceleration       A particle initially at position P(0), with velocity
cg                         vector V(0) and constant acceleration vector A,
cg                         obeys the following equations of motion:
cg
cg                           V(t)    = V(0) + A * t
cg                           VAVG(t) = 0.5 * (V(0) + V(t)) = V(0) + 0.5 * A * t
cg                           P(t)    = P(0) + VAVG(t) * t
cg                                   = P(0) + V(0) * t + 0.5 * A * t^2
cg
cg                         The path lies on a planar parabolic curve, in the
cg                         plane containing point P(0) and vectors V(0) and A.
cg
cg                         The vertex of the parabolic path is at the point
cg                         where the velocity and acceleration are perpendicular
cg                         to each other:
cg
cg                           V(tver) dot A =  V(0) dot A + A^2 tver = 0
cg                           tver          = -V(0) dot A / A^2
cg                           V(tver)       =  V(0) - (V(0) dot A) / A^2
cg
cg                         The path length may be obtained by integrating the
cg                         magnitude of the velocity vector over time.
cg
cg                           d(t) = Integral {|V(0) + A * t'| * dt'}, t' = 0, t,
cg
cg                         where the integrand |V(0) + A * t| is
cg
cg                           sqrt (V(0)^2 + 2 * V(0) dot A * t + A^2 * t^2)
cg
cg                         The integral may be found in a math handbook.
cg
cg                         If V(0) or A is zero or if V(0) and A are parallel,
cg                         the path is linear, and the path length is
cg
cg                           d(t) = VAVG(t) * t
cg
cg                         If two [or three] points on the particle path are
cg                         known at two or three times, the initial position
cg                         and velocity, and the zero [or constant] acceleration
cg                         may be found by solving the two [or three]
cg                         simultaneous linear equations of the particle path.
cg
cg                         The distance B between the particle and a plane
cg                         through the point Q with normal vector N is given by:
cg
cg                           B = (P(t) - Q) dot N / |N|
cg                             = (P(0) - Q) dot N + (V(0) dot N) * t +
cg                               0.5 * (A dot N) * t^2
cg
cg                         Any intersections between the particle path and the
cg                         plane may be found by setting B = 0 and solving for
cg                         t.  If no intersections exist, the proximal point
cg                         between the particle path and the plane occurs when
cg
cg                           V(t) dot N = 0 = (V(0) dot N) + (A dot N) * t
cg
cg                         or everywhere on the path if (A dot N) = 0.
cg
cg                         The point on the plane nearest the particle is at
cg
cg                           Q' = P(t) + ((Q - P(t)) dot N / |N|) * N
cg
cg                         The intersection between the particle path and a
cg                         quadric surface is obtained by substituting the
cg                         time-dependent coordinates of the particle into the
cg                         equation of the quadric surface, solving the
cg                         resulting quartic equation for any real time of
cg                         intersection, and calculating the particle
cg                         coordinates at that time.
cg
cg                         See command "accelerate".

cg    acceptable         An input line is acceptable if recognized as a comment
cg                         or a command.  An input argument is acceptable if
cg                         recognized as a command argument, is in the correct
cg                         mode, and if an integer or floating point number, is
cg                         within the allowed numerical range.

cg    accuracy           See "precision", "TOL", command "tol", command "big",
cg                         "error estimate", "significant figures".

cc    acos               An option in command "variable", argument FUNCTION,
cc                         to indicate the trigonometric inverse cosine
cc                         function.  A acos B means A * acos (B).

cf    acos               The trigonometric inverse cosine function.
cf                         Example:  y = acos (x) means y is the angle whose
cf                         cosine is x, and x = cos (y).  The result is in
cf                         radians, between 0 and pi.

cc    acosh              An option in command "variable", argument FUNCTION,
cc                         to indicate the inverse hyperbolic cosine function.
cc                         A acosh B means A * acosh (B).

cf    acosh              The inverse hyperbolic cosine function.
cf                         Example:  y = acosh (x) means y is the argument for
cf                         which the hyperbolic cosine is x, and x = cosh (y).
cf                         The range of x is x >= 1.
cf
cf                         acosh (x) = ln (x + sqrt (x^2 - 1)) (principal val)
cf                         acosh (x) = ln (x - sqrt (x^2 - 1)) (secondary val)

cg    add                See "add vectors".

cg    add                To add real or integer numbers, see commands
cg                         "variable, "big", "icalc".

cc    add                A synonym for sum in commands "quadric", "vector.
cc                         See commands "icalc", "variable", argument
cc                         FUNCTION, and command "big"..

cc    add                Following command "output", if the specified output
cc                         file already exists, and the current input is from
cc                         the user's terminal, the user must respond "add" to
cc                         allow GEOM to append to the existing output file.
cc                         This is the default if the current input is not from
cc                         the user's terminal.  To write over the existing
cc                         output file, the response must be "yes".
cc
cc                         Synonyms:  [add, a].

cg    add                See "add vectors".

cg    add vectors        See "vector sum".  See option "move" in commands:
cg                         axisym, cone, cylinder, ellipsoid, plane, point,
cg                         quadric, sphere.

cc    al                 A synonym for alias.

cg    alias              An alias may be used to replace all or part of a
cg                         frequently used long command line with a much shorter
cg                         substitute, for easier input.
cg
cg                         An alias is a delimited word up to 24 characters
c                          long, including any subscripts.
cg                         Its replacement is any character string up to 72
cg                         characters long or whatever will fit on the input
cg                         line of command "alias" (limited to 80 characters)
cg                         used to create the alias.  In any input line, an
cg                         initial word that is an alias will be replaced by the
cg                         replacement string.  This is done before symbol
cg                         replacement.  The alias replacement may contain
cg                         symbols, which will be replaced.
cg                         Only the first word of an input line containing
cg                         multiple statements can be replaced by an alias.
cg                         The combined number of characters resulting from the
cg                         replacement may not exceed 80.
cg
cg                         See "definition".
cg                         Also see "symbol", "synonym", "marker", command ".".
cg
cg                         The replacement string, if it is a single word that
cg                         contains no field delimiter, may itself be aliased to
cg                         another replacement string, but there may be no more
cg                         than 10 sequential replacements to find the final
cg                         string.  The maximum number of aliases is now 256.
cg
cg                         To repeat the preceding command many times, use
cg                         command ".", or create alias ANAME:
cg
cg                         alias ANAME = 'input command -1"
cg
cg                         Then after the command to be repeated, type
cg                         ANAME<return> as many times as desired.
cg
cg                         To repeat a single command "COMMAND ..." many times,
cg                         create alias ANAME (single characters near the
cg                         <return> key are convenient):
cg
cg                         alias ANAME = "COMMAND ..."
cg
cg                           Create alias ANAME, so that every time you
cg                           type "ANAME<return>", command "COMMAND ... "
cg                           will be executed.
cg
cg                         Then type ANAME<return> as many times as desired.
cg
cg                         To repeat a block of commands many times, execute
cg                         the block of commands once.  Then execute command
cg                         "input command ?" to find the indices N1 and N2 of
cg                         the first and last commands of the block of commands
cg                         saved in memory.
cg
cg                         Then create alias ANAME:
cg
cg                         alias ANAME = 'input command N1 N2'
cg
cg                           Create alias ANAME, so that every time you
cg                           type "ANAME<return>", stored commands N1 through
cg                           N2 are executed.
cg
cg                         Then type ANAME<return> as many times as desired.
cg
cg                         The following commands may affect or display aliases:
cg                         alias, copy, delete, help, last, list, rename,
cg                         repack, search, sort, tables.
cg
cg                         Synonyms:  [alias, al, a]. [command, c, cmd],
cg                         [input, call, i, in, r, rd, read].

cc    alias              An option in command "debug", to display GEOM internal
cc                         parameters and variables for aliases:  naliasm,
cc                         nalias, alias1, alias2, lalias2, alias1s, lalias1s.
cc                         Synonyms:  [alias, al, a].

cc    alias              Command to display one or more aliases or to create or
cc                         delete an alias.  An alias is a delimited word up to
cc                         24 characters long which, when the initial word of an
cc                         input line, is replaced by a specified character
cc                         string up to 72 characters long.
cc                         The combined number of characters resulting from the
cc                         replacement may not exceed 80.
cc                         Alias replacement is done before symbol replacement.
cc                         The alias replacement may contain symbols,
cc                         which will be replaced before executing the line.
cc                         Only the first word of an input line containing
cc                         multiple statements can be replaced by an alias.
cc                         See "do loop use".
cc
cc                         Note:  no replacement of symbols will be done
cc                         in this command.
cc
cc                         NOTE!  A warning message will be displayed if an
cc                         alias has the same name as a preset synonym or a
cc                         symbol or its replacement.
cc
cc                         Aliases may also be displayed with command
cc                         "synonymn".
cc
cc                         Forms include:
cc
ccin                       help alias
ccin                       alias [help]
cc
cc                           Display the command options.
cc
ccin                       alias [all,list]
cc
cc                           Display all alias pairs.
cc
ccin                       alias list ANAME1 ANAME2 ANAME3 ...
cc
cc                           Display the alias pairs for aliases ANAME1, ANAME2,
cc                           ANAME3, ..., including any aliases with subscripts
cc                           following the specified names.
cc
ccin                       alias ANAME
cc
cc                           Display the alias pair for alias ANAME.
cc
ccin                       alias ANAME = ''
cc                         delete alias ANAME
cc
cc                           Delete the alias pair for alias ANAME.
cc
ccin                       alias ANAME = 'STRING'
cc
cc                           Create alias ANAME with replacement string STRING.
cc                           If STRING is bracketed by single quotes, repeat any
cc                           internal single quotes.  If STRING is bracketed by
cc                           double quotes, repeat any internal double quotes.
cc                           ANAME may not contain the current field delimiter,
cc                           and should not contain any field delimiter that
cc                           will be in use when alias ANAME is used in a
cc                           command.  This might include any of the characters:
cc                           (blank) ,  :  <  >  [  \  ]  ^  _  `  {  |  }
cc                           STRING may contain blanks.
cc
cc                           Use "+" or "-" instead of ANAME to form the name
cc                           by incrementing or decrementing the base name for
cc                           aliases.  See command "last", "increment names".
cc
cc                           Note:  no replacement of symbols will be done
cc                           in this command.
cc
cc                           A warning message will be displayed if an alias has
cc                           the same name as a preset synonym.
cc
cc                         Synonyms:  [", ' (in pairs)], [alias, al, a],
cc                         [help, h].

cc    alias              An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on an alias.
cc                         Synonyms:  [alias, al, a].

cg    alias arrays       Aliases may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    aliases            Some suggested aliases, to shorten long "mesh" and
cg                         "plot" commands, are:
cg
cg                         alias dma   = "mesh - all"
cg                         alias dmbl  = "mesh - block"
cg                         alias dmcl  = "mesh - cluster"
cg                         alias dmp   = "mesh - point"
cg                         alias mbla  = "mesh block all"
cg                         alias mexbl = "mesh exchange block"
cg                         alias mins  = "mesh insert"
cg                         alias minv  = "mesh invert"
cg                         alias mlin  = "mesh linear"
cg                         alias mlst  = "mesh list"
cg                         alias mmv   = "mesh move"
cg                         alias mrx   = "mesh relax"
cg                         alias msz   = "mesh size"
cg                         alias mtst  = "mesh test"
cg                         alias pla   = "plot array"
cg                         alias plax  = "plot axis"
cg                         alias plcen = "plot center"
cg                         alias dpla  = "plot delete all"
cg                         alias dpli  = "plot delete index"
cg                         alias dplm  = "plot delete marker"
cg                         alias plim  = "plot limits"
cg                         alias plma  = "plot marker all"
cg                         alias plm   = "plot marker"
cg                         alias plpa  = "plot point all"
cg                         alias plpi  = "plot point index"
cg                         alias plpm  = "plot point marker"
cg                         alias plsz  = "plot size"
cg                         alias plst  = "plot status"
cg                         alias plt   = "plot title"
cg                         alias zoom  = "plot zoom"
cg                         alias prpa  = "project point all"
cg                         alias whpa  = "where point all"

cg    align              To move a quadric surface of type QTYPE (plane, sphere,
cg                         cylinder, cone, ellipsoid, axisym, quadric, hyperb),
cg                         with name QNAME, to the origin, and/or align its
cg                         symmetry axes with the major axes, execute the
cg                         following:
cg
cg                         point pcen QTYPE QNAME
cg
cg                           Create point pcen, the center of QNAME.
cg
cg                         vector vmove QTYPE QNAME
cg
cg                           Create vector vmove, pointing from the center of
cg                           QNAME to the origin.
cg
cg                         operator oprot QTYPE QNAME
cg
cg                           Create rotation operator oprot, to rotate the
cg                           symmetry axes of QNAME to the major axes.
cg
cg                         Move QNAME to the origin, then align it:
cg
cg                         move QTYPE QNAME vmove
cg
cg                           Translate QNAME to the origin.
cg
cg                         rotate QTYPE QNAME oprot
cg
cg                           Rotate QNAME (around the origin) to align its axes
cg                           with the major axes.
cg
cg                         Or, without first moving QNAME to the origin:
cg
cg                         rotate QTYPE QNAME oprot pcen
cg
cg                           Rotate QNAME (around point pcen) to align its axes
cg                           with the major axes.
cg
cg                         move QTYPE QNAME vmove
cg
cg                           Translate QNAME to the origin.
cg
cg                         See "center".

cc    all                An option in command "help", to display all help
cc                         messages.

cc    all                An option in commands, in place of an object name, to
cc                         indicate that all of the specified type of object are
cc                         to be processed.
cc
cc                         Do not name any object "all", but if you do, use
cc                         command "rename" to rename it, or command "delete"
cc                         to delete it.
cc
cc                         Commands that may affect all named objects include:
cc                         delete, last, list, repack, search, sort.

cc    all                An option in command "plot", to indicate that the
cc                         plot axis limits will include all plot points.

cc    ALNAME             The name of a line between two points.  May have up to
cc                         24 characters, and may be ASCII, integer or floating
cc                         point.  No line name may be "+", "-", "all", "h",
cc                         "help", "list" or "thru", begin with "!" or contain
cc                         ";".
cc                         Also referred to as ALNAME1, ALNAME2, ALNAME3, ...
cc                         Specified with command "line".
cc
cc                         Lines may appear in commands:
cc                         accelerate, cone, copy, delete, distance, help, last,
cc                         line, list, rename, repack, search, sort, track,
cc                         vector.

cc    alph               A synonym for commands.

cc    alph               An option in command "help", to display an alphabetic
cc                         list of command words, including synonyms.

cg    alphabetic         See "alphabetic order".

cg    alphabetic order   To list all commands and their synonyms in alphabetic
cg                         order, use commands "commands" and "synonyms".

cg    altitude           An altitude of a triangle is a line from a vertex
cg                         perpendicular to the opposite edge.  The three
cg                         altitudes intersect at the orthocenter.
cg                         See "median", "bisector", "trig".

cc    AMNAME             In commands "marker" and "plot", any single character,
cc                         except that no marker name may be "!", ";", "+",
cc                         "-" or "h".
cc                         Also referred to as AMNAME1, AMNAME2, AMNAME3, ...
cc                         May include numbers, upper and lower case letters,
cc                         control characters, tabs, etc, but not the current
cc                         field delimiter.

cg    amu                Atomic mass units.
cg                         1 amu = 9.3149432E8 eV (+/- 0.3 ppm).

cc    ANAME              In command "alias", any delimited string up to
cc                         24 characters long, except that no alias name may be
cc                         "+", "-", "all", "h", "help", "list" or "thru",
cc                         begin with "!" or contain ";".
cc                         Also referred to as ANAME1, ANAME2, ANAME3, ...
cc                         May include numbers, upper and lower case letters,
cc                         control characters, tabs, etc, but not the current
cc                         field delimiter.

cg    and                The and or ampersand character, "&".

cc    ang                A synonym for angle.

cc    ang                A synonym for angles in command "angles".

cc    ANG1               See "ANG1, ANG2".

cc    ANG1, ANG2         In command "cone", the first and last vertex
cc                         half-angles of a family of nested cones with the same
cc                         vertex point and axis.

cc    ANG1, ANG2         In command "vector", option "angle", the angles between
cc                         the unit vector being created and vectors VNAME1
cc                         and VNAME2, respectively, in the current angle units.

cc    ANG2               See "ANG1", ANG2.

cc    ANGLE              In command "angles", an angle, specified in degrees,
cc                         radians or grads.
cc                         Also referred to as ANGLE1, ANGLE2, ANGLE3, ...,
cc                         ANGLEN.
cc                         May be integer, floating point or a variable.
cc                         Absolute value in degrees may not exceed the largest
cc                         machine integer.

cc    ANGLE              In command "cone", the half-angle of the cone at
cc                         the vertex.
cc                         See "angles", "DANGLE".

cc    ANGLE              In command "operator", option "axial", the angle
cc                         (counterclockwise, with the axis pointed at the
cc                         observer) of rotation around the axis vector VAXIS.
cc                         See "angles", "DANGLE".
cc                         Note:  angle ANGLE may be sampled randomly.

cc    ANGLE              In command "vector", options "random" and "angle",
cc                         the fixed scattering angle from a specified axis.
cc                         May be integer, floating point or a variable.
cc                         Specified in the current angle units.
cc                         See "angles", "DANGLE".
cc                         Note:  angle ANGLE may be sampled randomly.

cc    angle              A synonym for angles in command "angles".

cc    angle              An option in command "trig", indicating that the next
cc                         argument is a positive vertex angle of a triangle,
cc                         in the current angle units, and less than 180
cc                         degrees or pi radians.
cc                         Synonyms:  [angle, ang].

cc    angle              An option in command "variable", to find the angle
cc                         between two vectors, in the current angle units.
cc                         Synonyms:  [angle, ang].

cc    angle              An option in command "vector", to create a unit vector
cc                         at specified angles from two specified vectors.
cc
cc                         Given a tetrahedron with the three vertex points P1,
cc                         P2 and P3, to find the fourth vertex point P4 such
cc                         that the edge from P1 to P4 makes angle ANG12 with
cc                         the edge from P1 to P2, makes angle ANG13 with the
cc                         edge from P1 to P3, and has length EDGE14, use the
cc                         following commands:
cc
cc                         vector V12 point P1 P2
cc                         vector V13 point P1 P3
cc                         vector V14 angle ANG12 V12 ANG13 V13
cc                         copy point P1 P4
cc                         move point P4 V14 EDGE14

cc    angle              An option in command "vector", to have the vector
cc                         randomly sampled from a uniform distribution of
cc                         azimuth angles around a specified axis vector VAXIS,
cc                         at a fixed angle ANGLE from VAXIS.
cc                         Note:  angle ANGLE itself may be sampled randomly.

cg    angle              See "angle of incidence", "angle of rotation",
cg                         "angle units", "angle, central", "angle, dihedral",
cg                         "angles", "scatter angle".

cg    angle              To find the angle between two vectors, use command
cg                         "variable", option "angle".  The angle is that
cg                         measured from one vector to the other, at the vertex
cg                         formed by placing the tails (the initial points) of
cg                         the two vectors together, so is always between 0 and
cg                         180 degrees (between 0 and pi radians.)

cg    angle of incidence
cg                       The angle of incidence between a linear track and a
cg                         line is the angle between the track and the line at
cg                         the point of intersection.
cg                         The angle of incidence between a linear track and a
cg                         surface is the angle between the track and the vector
cg                         normal to the surface at the point of intersection.

cg    angle of rotation
cg                       A rotation operator OPNAME, specified with command
cg                         "operator", has associated with it an angle
cg                         of rotation around a particular axis, and three
cg                         sequential angles of rotation around the x, y and z
cg                         axes.  These may be displayed with command
cg                         "operator OPNAME".

cg    angle units        See "angles".

cg    angle, central     The central angle is the angle between the two lines
cg                         from a central point to any other two points.

cg    angle, dihedral    The dihedral angle is the angle between two
cg                         intersecting planes.

cc    angles             An option in command "debug", to display GEOM internal
cc                         variables for the coordinate system and angles:
cc                         asys, acoordu, acoordv, acoordw, angunit.
cc                         Synonyms:  [angles, angle, ang].

cc    angles             Command to display or specify the units for angles,
cc                         degrees (default) or radians or to convert angles
cc                         from one unit to another.
cc                         Display of point coordinates and vector components
cc                         will be in the specified angle units, unless
cc                         specifically labeled otherwise.
cc                         See "coordinate conversion", "vector conversion".
cc                         Note:  variables are not affected by changes
cc                         in the angle units, so their values and units remain
cc                         as intended by the user when originally specified.
cc                         Variables may be assigned a descriptive tag to
cc                         specify the units or other data.
cc                         See command "variable", option "tag".
cc
cc                         Command "angles" relates to objects:  symbol,
cc                         variable.
cc
cc                         Forms include:
cc
ccin                       help angles
ccin                       angles help
cc
cc                           Display the command options.
cc
ccin                       angles
cc
cc                           Display the current angle units, and
cc                           display the command options.
cc
ccin                       angles [degrees,radians]
cc
cc                           Set the angle units to [degrees, radians].
cc
ccin                       angles UNIT1 UNIT2 ANGLE1 ANGLE2 ANGLE3 ...
cc
cc                           Convert from UNIT1 ("degrees", "grads" or
cc                           "radians") to UNIT2 ("degrees", "grads", "radians"
cc                           or "dms"):  ANGLE1, ANGLE2, ANGLE3, ...
cc                           The absolute value of ANGLE1, ANGLE2 or ANGLE3, ...
cc                           in degrees must not exceed the largest machine
cc                           integer.
cc
ccin                       angles dms UNIT2 DEGREES MINUTES SECONDS
cc
cc                           Convert from degrees, minutes, seconds to UNIT2
cc                           ("degrees", "grads" or "radians").
cc                           The absolute values of DEGREES, MINUTES and SECONDS
cc                           in degrees must not exceed the largest machine
cc                           integer.
cc
ccin                       angles UNIT1 UNIT2 ANGLE1 thru ANGLEN
cc
cc                           Convert from UNIT1 ("degrees", "grads" or
cc                           "radians) to UNIT2 ("degrees", "grads", "radians"
cc                           or "dms"):  all stored variables with names in the
cc                           range from ANGLE1 thru ANGLEN.
cc                           The absolute values of ANGLE1 thru ANGLEN
cc                           in degrees must not exceed the largest machine
cc                           integer.
cc
cc                         Conversion between degrees and radians:
cc                           degrees = radians * 180 / pi
cc                           radians = degrees * pi / 180
cc                           See "deg/rad", "pi", "rad/deg".
cc
cc                         See command "coordinate" to specify the coordinate
cc                         system.
cc
cc                         Synonyms:  [angles, angle, ang],
cc                         [degrees, deg, degree], [grads, grad].
cc                         [help, h], [radians, rad, radian].

cc    ANGUNIT            The name of the unit for measuring angles, degrees
cc                         (default) or radians.  Specified with command
cc                         "angles".

cg    annular            See "annulus", "annular disk", "disk".

cg    annular disk       See "disk".

cg    annulus            An annulus is the space between two surfaces at
cg                         different radii from a central point or an axis.
cg                         See "disk".
cg                         To create zones consisting of cylindrical or
cg                         spherical annuli, use command "cylinder" or "sphere",
cg                         option "concentric" or "scale", and command "zone".

cg    appended           See "appended comment".

cg    appended comment   To append a comment to any input line, precede the
cg                         comment with the field delimiter and the character
cg                         "!".  Do not begin the name of any alias, marker or
cg                         other object with the character "!".

cg    approximation      A good approximation to the decimal part of a number
cg                         may be obtained by finding the first few terms of
cg                         the continued fraction for the number (see
cg                         "continued fraction", command "contfr"), or the first
cg                         few terms of the number expressed as a series of
cg                         reciprocals of integers (see "reciprocal series",
cg                         command "iris").

cg    APT                The All-Particle Tracking subroutine library.
cg                         APT subroutines currently called directly by GEOM:
cg                         aptaxis, aptbang, aptbite, aptbrkn, aptbrkp, aptbrks,
cg                         aptbrkv, aptcang, aptchai, aptchap, aptchfp, aptchfs,
cg                         aptchia, aptchin, aptchmv, aptchrn, aptchrp, aptchsq,
cg                         aptcinc, aptcirc, aptcirk, aptcirp, aptclis, aptcris,
cg                         aptcsys, aptcsyv, aptcube, aptcubs, aptcycy, aptdode,
cg                         aptetrn, aptetrp, aptetru, aptetrw, aptexpl, aptffip,
cg                         aptgrat,
cg                         apticos, aptintq, aptlnlc, aptlnln, aptlnpl, aptlocd,
cg                         aptlocs, aptmaxw, aptmopv, aptnewt, aptnint, aptnorm,
cg                         aptocta, aptparb, aptparh, aptparl, aptparp, aptparq,
cg                         aptpars, aptpart, aptparx, aptpers, aptpfit, aptplcy,
cg                         aptplis, aptplpl, aptplqu, aptplsp, aptpolf, aptpoly,
cg                         aptprcy, aptprop, aptprsp, aptptln, aptptpl, aptqexc,
cg                         aptqext, aptqexv, aptqfit, aptqhyp, aptqnor, aptqper,
cg                         aptqprr, aptqprt, aptqrts, aptquar, aptqupr, aptrabc,
cg                         aptradv, aptrcut, aptrefq, aptrefs, aptrext, aptrich,
cg                         aptrins, aptripl, aptripq, aptrips, aptripv, aptrkis,
cg                         aptrlop, aptrois, aptrota, aptrotq, aptrots, aptrott,
cg                         aptrotv, aptscan, aptscat, aptscav, aptsciz, aptscll,
cg                         aptsclr, aptslid, aptsolv, aptspcy, aptspha, aptsphk,
cg                         aptsphp, aptspod, aptspsp, aptsver, apttetd, apttetr,
cg                         apttlod,
cg                         apttran, apttrig, apttrip, apttris, aptvadd, aptvang,
cg                         aptvaxb, aptvdis, aptvdot, aptvpln, aptvplp, aptvsum,
cg                         aptvunb, aptvunz, aptvusz, aptvxun, aptwhis, aptwirl,
cg                         aptwist, aptxnup, ranf.
cg
cg                         Many others are called by these.  See file apt.link
cg                         in directory ~edwards/work/apt/doc .
cg                         See files geom_apt_calls, geom_apt_called_by .

cn    apt.link           A file listing all links between APT subroutines.
cn                         In directory ~edwards/work/apt/doc .

cn    aptflibe           The TAR library of APT subroutine source files.
cn                         in ~edwards/work/apt/src on the open YANA Cluster.
cn                         in /users/u47/edwards/apt/src on FAST archive.
cn                         See "libapt.a".

cc    AQU                See "AQU, AQV, AQW".

cc    AQU, AQV, AQW      In command "zone", the name of the initial quadric
cc                         surface in a family of quadric surfaces.

cc    AQV                See "AQU, AQV, AQW".

cc    AQW                See "AQU, AQV, AQW".

cc    arc                Command to find, at a point on one of a family of
cc                         quadric surfaces, the normal vector; the number of
cc                         curves passing through the point, and lying in the
cc                         surface, and in a plane containing the normal vector,
cc                         having zero or extreme curvature; and for each such
cc                         curve, the corresponding radius of curvature, center
cc                         of curvature, and unit direction vector along the
cc                         curve u = (ux, uy, uz).  See "vector field",
cc                         "principal radius", command "extrema".
cc
cc                         Command "arc" relates to objects:  axisym, cone,
cc                         cylinder, ellipsoid, hyperb, plane, point, quadric,
cc                         sphere, symbol.
cc
cc                         Forms include:
cc
ccin                       help arc
ccin                       arc [help]
cc
cc                           Display the command options.
cc
ccin                       arc PNAME QNAME
cc
cc                           Find, at point PNAME on a member of the family of
cc                           quadric surfaces represented by quadric surface
cc                           QNAME: the normal vector; the number of curves
cc                           passing through point PNAME, and in a plane
cc                           containing the normal vector, having zero or
cc                           extreme curvature; and for each such curve,
cc                           the corresponding radius of curvature, center of
cc                           curvature, and unit direction vector along the
cc                           curve through point PNAME.
cc                           If any of the surface curves has zero curvature,
cc                           the surface is a ruled surface.
cc                           If QNAME is a plane, four straight lines, at 45
cc                           degree intervals, will be returned.
cc
cc                         Synonyms:  [help, h]

cg    Archimedean        See "archimedean spiral".

cg    Archimedean spiral
eg                       An Archimedean spiral is a curve in a plane
cg                         perpendicular to an axis, with its radial distance
cg                         from the axis a linear function of the angular
cg                         coordinate around the axis, with the angle ranging
cg                         continuously from zero to infinity.
cg                         To generate a family of points arrayed along an
cg                         Archimedean spiral, use command "point ... move" to
cg                         create a family of points along a straight line
cg                         perpendicular to the axis, then use command "cluster"
cg                         to create a cluster consisting of the points, and
cg                         then operate on the cluster with command "twist",
cg                         option "radial".

cn    archive            A file containing a list of all files last saved in
cn                         the archives.

cg    area               See "area of brick", "area of disk", "area of polygon",
cg                       "area of quadric", "area of revolution", "area units".

cc    area               Command to find the projected area of a general or
cc                         regular polygon, the average edge length, and the
cc                         average of the vertex points.
cc
cc                         Command "area" relates to objects: cluster, point,
cc                         symbol, vector.
cc
cc                         Forms include:
cc
ccin                       help area
ccin                       area [help]
cc
cc                           Display the command options.
cc
ccin                       area VNORM point PNAME1 PNAME2 PNAME3 ...
cc
cc                           Find the area projected perpendicularly onto a
cc                           plane with normal vector VNORM, of the general
cc                           polygon with three or more vertex points PNAME1,
cc                           PNAME2, PNAME3, ..., which need not be coplanar.
cc                           Also display the average of the vertex points, and
cc                           the average edge length.
cc
ccin                       area VNORM cluster CLNAME
cc
cc                           Find the area projected perpendicularly onto a
cc                           plane with normal vector VNORM, of the general
cc                           polygon formed by the points in the cluster CLNAME,
cc                           which need not be coplanar.  Also display the
cc                           average of the vertex points, and the average edge
cc                           length.
cc
cc                         Synonyms:  [cluster, cl], [help, h],
cc                         [point, p, pnt, pt].

cg    area               To find the area of the parallelogram or triangle
cg                         between two vectors, use command "cross".
cg                         The parallelogram or triangle is that formed by
cg                         placing the tails (the initial points) of the two
cg                         vectors together, and completing the figure.
cg                         To find the area of the triangle specified by three
cg                         points, use command "triangle".
cg                         To find the area of the triangle specified by three
cg                         of its parts (three edges and three angles), use
cg                         command "trig".
cg                         To find the area of a regular polygon, use command
cg                         "polygon".
cg                         To find the projected area of a regular or general
cg                         polygon, use command "area".
cg                         To find the area of a circle, use command "circle",
cg                         "disk" or "intcirc".
cg                         To find the area of an annular disk, use command
cg                         "disk".
cg                         To find the surface area of a sphere or the cross
cg                         section area of a circular cylinder, use command
cg                         "cylinder" or "sphere".
cg                         To find the areas of the faces of a "brick", use
cg                         command "brick".
cg                         To find the area of the faces of a regular
cg                         polyhedron, use command "polyhedron".
cg
cg                         To find other areas, use command "area".

cg    area of brick      The area AREA(u) of a surface with a fixed value of one
cg                         of the coordinates u of an orthogonal coordinate
cg                         system (u, v, w), and bounded by two fixed values of
cg                         each of the other two coordinates v and w, is given
cg                         below.
cg                         Cartesian coordinates (x, y, z):
cg                           AREA(x)     = (Y2 - Y1) * (Z2 - Z1)
cg                           AREA(y)     = (Z2 - Z1) * (X2 - X1)
cg                           AREA(z)     = (X2 - X1) * (Y2 - Y1)
cg                         Cylindrical coordinates (rcyl, theta, z)
cg                           (cylindrical radius, azimuthal angle, z axis)
cg                           (rcyl => 0, 0 <= theta <= 2*pi):
cg                           AREA(rcyl)  = rcyl * (Z2 - Z1) * (theta2 - theta1)
cg                           AREA(theta) = (rcyl2 - rcyl1) * (Z2 - Z1)
cg                           AREA(z)     = (rcyl2^2 - rcyl1^2) *
cg                                         (theta2 - theta1) / 2
cg                           Angle theta = arctan (y / x), in radians, and
cg                           pi = 3.141592653589793...
cg                         Spherical coordinates (rsph, theta, phi)
cg                           (spherical radius, azimuthal angle, polar angle)
cg                           (rsph => 0, 0 <= theta <= 2*pi, 0 <= phi <= pi):
cg                           AREA(rsph)  = rsph^2 * (cos (phi1) - cos (phi2)) *
cg                                         (theta2 - theta1)
cg                           AREA(theta) = (rsph2^2 - rsph1^2) *
cg                                         (phi2 - phi1) / 2
cg                           AREA(phi)   = (rsph2^2 - rsph1^2) * sin (phi) *
cg                                         (theta2 - theta1) / 2
cg
cg                         See "brick".

cg    area of disk       The annular area of an annular disk with inner radius
cg                         RADKIN and outer radius RADKOUT is:
cg                         AREADK = pi * (RADKOUT^2 - RADKIN^2)
cg                         The inner area (the "hole") is:
cg                         AREAH  = pi * RADKIN^2
cg                         pi = 3.141592653589793...

cg    area of polygon    The area of a polygon in the plane z = 0, with N
cg                         vertices, is given by the absolute value of:
cg                         area = 0.5 * sum(i = 1, N) {(x(i) + x(i+1)) *
cg                         (y(i) - y(i+1))}, where N + 1 -> 1.
cg                         See command "area".
cg
cg                         The area of any plane figure, projected onto a plane,
cg                         is equal to the original area multiplied by the
cg                         cosine of the angle between the normal vectors of the
cg                         two planes.  See commands "dot" and "variable".
cg
cg                         To find the area of the faces of a regular
cg                         polyhedron, use command "polyhedron".

cg    area of quadric    See "ellipsoid", "sphere".

cg    area of revolution
cg                       An area of revolution, formed by rotating the line
cg                         with end points (rcyl1, z1) and (rcyl2, z2) around
cg                         the z axis from azimuthal angle theta1 to azimuthal
cg                         angle theta2:
cg                         AREA = ((rcyl1 + rcyl2) / 2) *
cg                                (z2 - z1) * (theta2 - theta1)

cg    area units         See "conv.mac", "conversion factors".

cc    ARGUMENT           An argument in an input line.  Always delimited on the
cc                         left by the beginning of the line or a field
cc                         delimiter, and on the right by a field delimiter or
cc                         the end of the line (80 characters).  If the field
cc                         delimiter is a blank character, initial and trailing
cc                         blanks are ignored, and multiple blanks are treated
cc                         as a single blank.  If the field delimiter is not a
cc                         blank character, trailing null fields are ignored,
cc                         but an initial null field is an error.  Do not begin
cc                         an input line with a non-blank field delimiter.
cc                         The field delimiter is initially a blank character,
cc                         but may be changed with command "delimiter".
cc                         The argument may be ASCII, integer, floating point,
cc                         a variable whose value has the same mode as the
cc                         argument, or a symbolic word which, after symbol
cc                         replacement, has the same mode as the argument.
cc                         See command "variable".

cg    arguments          Command arguments are displayed in lower case for
cg                         arguments to be typed literally as shown, and in
cg                         UPPER CASE for arguments for which the user must
cg                         provide a value, which may be ASCII, an integer or
cg                         floating point variable name, an integer or floating
cg                         point value, or a word which when modified by symbol
cg                         replacement, is one of the above.
cg                         The first argument of a command, the command word
cg                         itself, is always in lower case.
cg
cg                         With certain exceptions (see "symbol"), any argument,
cg                         may be replaced by a symbolic word which, after
cg                         symbol replacement, must be an acceptable value for
cg                         the argument, including the name of an integer or
cg                         floating point variable or a literal argument.
cg
cg                         Any argument which allows a floating point value may
cg                         also be replaced by the name of an integer or
cg                         floating point variable, or by a symbolic word which,
cg                         after symbol replacement, is an integer or floating
cg                         point value.  See "VARNAME".
cg
cg                         Any argument which only allows an integer value may
cg                         also be replaced by an integer variable, or by a
cg                         symbolic word which, after following symbol
cg                         replacement, is an integer value, except for the
cg                         argument LINE in command "indo" or "redo".
cg
cg                         With certain exceptions, arguments are always
cg                         delimited from other arguments by the current
cg                         field delimiter (see command "delimiter"), so cannot
cg                         contain internal field delimiters.  The exceptions
cg                         are the argument STRING in command "alias",
cg                         the argument TEXT in command "marker", and the
cg                         argument ENTRY in command "define", which must also
cg                         be bracketed by single or double quotes.

cc    arguments          Numerical values that are arguments in commands, and
cc                         may be replaced by a variable or a symbolic word
cc                         which, after symbol replacement, is a variable,
cc                         include:
cc
cc                         Integer only     Commands
cc                         --------------   --------
cc                         I1, I2, I3       indo
cc                         INC              variable, vector, point, plane
cc                         INC              sphere, cylinder, cone, ellipsoid
cc                         INC              axisym, quadric, brick, tetrahedron
cc                         INC              zone, increment
cc                         INCR             symbol
cc                         INT1, INT2, ...  big
cc                         IP1,IP2,IP3,IP4  tetrahedron
cc                         IQ1, IQ2, ...    zone
cc                         IQU,IQV,IQW      zone
cc                         IVAR             variable
cc                         IZU,IZV,IZW      zone
cc                         K, L, M          mesh, variable
cc                         K1, K2           mesh
cc                         KMAX,LMAX,MMAX   mesh
cc                         KMOVE,LMOVE      mesh
cc                         L1, L2           mesh
cc                         M1, M2           mesh
cc                         M1, M2, M3       factor
cc                         MINUTES          angles
cc                         MMOVE            mesh
cc                         N                icalc, spin
cc                         N1, N2           mesh, plot
cc                         N3               plot
cc                         NCOLUMNS         plot
cc                         NITMAX           root
cc                         NLINES           plot
cc                         NQU,NQV,NQW      zone
cc                         NSAMP            sample
cc                         NUMAX            axisym
cc                         NUMBR            brick
cc                         NUMCONE          cone
cc                         NUMCYL           cylinder
cc                         NUMDIR           proximal
cc                         NUMELL           ellipsoid
cc                         NUMLINE          line
cc                         NUMPL            plane
cc                         NUMPT            point
cc                         NUMQ             quadric
cc                         NUMSPH           sphere
cc                         NUMSTR           increment
cc                         NUMT             ratio
cc                         NUMTET           tetrahedron
cc                         NUMTR            triangle
cc                         NUMV             vector
cc                         NUMVAR           variable
cc                         NUMZN            zone
cc                         NVER             polygon, polyhedron
cc
cc                         Integer or
cc                         floating point   Commands
cc                         --------------   --------
cc                         A                variable
cc                         A(0), A(1), ...  root
cc                         A0, A1, A2, ...  roots
cc                         ABSLEN           vector
cc                         ANG1, ANG2       cone
cc                         ANGLE            cone, operator, quadric
cc                         ANGLE1-ANGLEN    angles
cc                         AQU, AQV, AQW    zone
cc                         AVAR             variable
cc                         AXQ(1), AXQ(2)   axisym
cc                         B                variable
cc                         BTEMP            bin
cc                         DANGLE           plane
cc                         DEGREES          angles
cc                         DEV              bin
cc                         DMAX             walk
cc                         DMEAN            walk
cc                         DPR              bin
cc                         DPRL, DPRR       bin
cc                         DT               accelerate
cc                         DU, DV, DW       vector, plane, slice
cc                         DX               root
cc                         F1, F2, ..., FN  variable
cc                         FACT             quadric
cc                         FADD             variable
cc                         FMULT            brick, variable
cc                         FU, FV, FW       point
cc                         FVAR             variable
cc                         PATHMAX          walk
cc                         PHI              point
cc                         PITCH            twist
cc                         POW              bin
cc                         POWER            bin
cc                         PRTOT            bin
cc                         PTL, PTR         project
cc                         QC to QZZ        quadric
cc                         R1, R2, R3       redo
cc                         RAD1, RAD2       sphere, cylinder, kiss
cc                         RAD3, RAD4       kiss
cc                         RADIUS           point, sphere, cylinder
cc                         RADIUS1, RADIUS2 intcirc
cc                         RADKIN           disk
cc                         RADKOUT          disk
cc                         RATIO            bin, operator
cc                         RCYL             point
cc                         RELLEN           vector
cc                         RINV             twist
cc                         RSPH             point
cc                         SAX, SAY, SAZ    ellipsoid
cc                         SCENH, SCENV     plot
cc                         SECONDS          angles
cc                         SIGMA            bin
cc                         SMAX, SMIN       plot
cc                         SUM              ratio
cc                         T1, T2, T3       accelerate
cc                         TERM1            ratio
cc                         THETA            point, vector, plane
cc                         TMAX, TMIN       accelerate
cc                         TOL              tol
cc                         U, V, W          vector, plane, intcirc
cc                         U1, U2           intcirc
cc                         UANGLE           operator
cc                         UMAX, UMIN       brick
cc                         V1, V2           intcirc
cc                         VACC             accelerate
cc                         VAL              quadric
cc                         VALUE            variable
cc                         VANGLE           operator
cc                         VINIT            accelerate
cc                         VMAX, VMIN       brick
cc                         VMULT            move
cc                         VMULT1, VMULT2   vector
cc                         VNORM            area, disk, plane, project
cc                         VRAN             bin
cc                         VRANL, VRANR     bin
cc                         W1,W2,W3,W4      point
cc                         WANGLE           operator
cc                         WMAX, WMIN       brick
cc                         X(1), X(2), ...  root
cc                         X, Y, Z          point
cc                         X1,X2,X3,X4      roots (real part)
cc                         XMAX, XMIN       root
cc                         XROOT            rootf
cc                         Y1,Y2,Y3,Y4      roots (imaginary part)
cc                         ZOOMULT          plot
cc                         ZVOL             zone

cc    arith              A synonym for arithmetic.

cc    arithmetic         An option in command "debug", to display GEOM internal
cc                         parameters and variables for integer and floating
cc                         point arithmetic:  idmax, amode, abind, iemax, tol.
cc                         These include the maximum size of integers and
cc                         floating point machine words, the number base for
cc                         input to command "icalc", and the option for display
cc                         of the binary form of output from command "icalc".
cc                         See commands "icalc", "tol", "big".
cc                         Synonyms:  [arithmetic, arith].

cg    arithmetic         See "arithmetic series".

cg    arithmetic         Arithmetic may be done on floating point and integer
cg                         values with command "variable".
cg                         Arithmetic may be done on integer values with
cg                         commands "icalc", "big".
cg
cg                         The real and/or complex roots of a quadratic, cubic
cg                         or quartic polynomial equation with real coefficients
cg                         may be found with command "roots".
cg
cg                         The real coefficients of a polynomial equation with
cg                         from two to four specified real and/or complex roots
cg                         may be found with command "roots", option "=".
cg
cg                         The real coefficients of an Nth-order polynomial
cg                         equation with N specified real roots may be found
cg                         with command "root", option "=".
cg
cg                         To search for real roots, extrema and inflection
cg                         points of a polynomial equation using Newtonian
cg                         iteration, use command "root".
cg
cg                         The value of a quadratic, cubic or quartic polynomial
cg                         equation with real coefficients may be found for any
cg                         real or complex argument with command "roots",
cg                         option "?".
cg
cg                         The value of a polynomial with specified coefficients
cg                         and a specified argument may be found with command
cg                         "variable", option "polynomial".
cg
cg                         The ratio for a geometric series with a given sum
cg                         first term and number of terms may be found using
cg                         command "ratio".
cg
cg                         To find the continued fraction for a decimal number,
cg                         or vice versa, use command "contfr".
cg
cg                         To find the equivalent of a decimal number, expressed
cg                         as an integer plus a sum of reciprocals of integers,
cg                         use command "iris".

cg    arithmetic series
cg                       An arithmetic series is one in which the value of each
cg                         term after the first term differs from the preceding
cg                         term by an additive constant.  To create a family of
cg                         variables whose values form an arithmetic
cg                         series:
cg
cg                         variable VAR(1) = VALUE
cg
cg                           Create variable VAR(1), with the value of the
cg                           first term.
cg
cg                         variable VAR(2) series NUMVAR INC VAR(1) FADD 1
cg
cg                           Create a series of NUMVAR variables VAR(2),
cg                           ..., with names incremented by INC characters
cg                           (or INC digits, if an integer name or a name with
cg                           one or more integer subscripts), each equal to the
cg                           preceding variable plus FADD, starting from
cg                           variable VAR(1).
cg                           See "increment names".
cg
cg                         Alternately, using subscripts and a do loop:
cg
cg                         variable VAR(1) = VALUE
cg                         do NL 2 NUMVAR
cg                           variable NLM = NL - 1
cg                           variable VAR(NL) = VAR(NLM) + FADD
cg                         enddo
cg
cg                         To create a family of points, planes or quadric
cg                         surfaces in which the distance of each from an
cg                         invariant point, axis or plane forms an arithmetic
cg                         series, use option "move" of commands "point",
cg                         "sphere", "cylinder", "cone", "ellipsoid", "axisym"
cg                         or "quadric", or use command "plane", option
cg                         "parallel".

cg    array              See "array shape", 'array sizes".

cc    array              An option in command "rename", to replace the stem name
cc                         of all members of an array with a new stem name.  A
cc                         stem name without a subscript will also be replaced.

cc    array              An option in command "plot", to display the plot array,
cc                         and all of the plot parameters.

cg    array              An object with a name of the form OBJNAME(N),
cg                         OBJNAME_N. or OBJNAME.N, where N may have more than
cg                         one value, is a member of an array.
cg                         The form using parentheses, with a variable name
cg                         for N, may be used for any object.

cg    array shape        A two-dimensional array x(i,j), i = 1, imax,
cg                         j = 1, jmax, is equivalent to a one-dimensional
cg                         array y(n), n = 1, kmax,
cg                         kmax = imax * jmax,
cg                         n    = j + jmax * (i - 1),
cg                         i    = 1 + (n - 1) / jmax,
cg                         j    = 1 + mod (n - 1, jmax).
cg
cg                       A three-dimensional array x(i,j,k), i = 1, imax,
cg                         j = 1, jmax, k = 1, kmax, is equivalent to a
cg                         one-dimensional array y(n), n = 1, nmax, where
cg                         nmax = imax * jmax * kmax,
cg                         n    = k + kmax * (j - 1) + kmax * jmax * (i - 1),
cg                         i    = 1 + (n - 1) / (jmax * kmax),
cg                         j    = 1 + mod ((n - 1) / kmax, jmax),
cg                         k    = 1 + mod ((n - 1), kmax).
cg
cg                       See "shape".

cg    array sizes        See "maximum number", commands "tables", "mesh".

cg    arrays             See "subscript", "subscripted names", "do loops",
cg                         commands "do" and "enddo".

cg    ASCII              See "ASCII variable", "ASCII word".

cg    ASCII              When used to describe arguments in commands, ASCII
cg                         means symbolic, i.e., not explicitly integer or
cg                         floating point.  See "integer input",
cg                         "floating point".
cg
cg                         ASCII characters are The set of characters used for
cg                         data of type character.
cg
cg                         The order of available keyboard characters is:
cg
cg                         (blank)  !  "  #  $  %  &  '  (  )    *  +  ,  -
cg                         .  /   0-9  :  ;  <  =  >  ?  @  A-Z  [  \  ]  ^
cg                         _  `   a-z  {  |  }  ~
cg
cg                         See "character set".
cg
cg                         Objects may be sorted into ASCII order of their
cg                         names, using command "sort", with options to sort
cg                         into increasing, decreasing or random order.
cg
cg                         For the order of entries in this file, case is
cg                         ignored.

cg    ASCII variable     See "symbol", command "symbol".

cg    ASCII word         See "ASCII", "commands", "key words".

cc    asin               An option in command "variable", argument FUNCTION,
cc                         to indicate the trigonometric inverse sine
cc                         function.  A asin B means A * asin (B).

cf    asin               The trigonometric inverse sine function.
cf                         Example:  y = asin (x) means y is the angle whose
cf                         sine is x, and x = sin (y).  The result is in
cf                         radians, between -pi and pi.

cc    asinh              An option in command "variable", argument FUNCTION,
cc                         to indicate the inverse hyperbolic sine function.
cc                         A asinh B means A * asinh (B).

cf    asinh              The inverse hyperbolic sine function.
cf                         Example:  y = asinh (x) means y is the argument for
cf                         which the hyperbolic sine is x, and x = sinh (y).
cf
cf                         asinh (x) =  ln ( x + sqrt (x^2 + 1)), x >= 0,
cf                         asinh (x) = -ln (-x + sqrt (x^2 + 1)), x <= 0.

cg    ASSIGNED           In the display for a point, indicates a mesh point,
cg                         assigned a set of mesh indices (k, l, m).

cg    asymptotes         The asymptotes of a hyperbola, a hyperbolic cylinder,
cg                         or a hyperboloid are the intersecting lines,
cg                         intersecting planes, or the cone, respectively,
cg                         resulting from changing the constant term in the
cg                         equation of the quadric curve or surface to zero.

cg    at symbol          The "at" symbol, "@".

cc    atan               An option in command "variable", argument FUNCTION,
cc                         to indicate the trigonometric inverse tangent
cc                         function.  A atan B means A * atan (B).

cf    atan               The trigonometric inverse tangent function.
cf                         Example:  y = atan (x) means y is the angle whose
cf                         tangent is x, and x = tan (y).  The result is in
cf                         radians, between -pi and pi.

cc    atan2              An option in command "variable", argument FUNCTION,
cc                         to indicate the trigonometric inverse tangent
cc                         function.  A atan2 B means atan2 (A, B)

cf    atan2              The trigonometric inverse tangent function, with two
cf                         arguments.  Example:  z = atan2 (x, y) means z is the
cf                         angle whose tangent is x / y, or tan (z) = x / y.
cf                         The result is in radians, between -pi and pi, in the
cf                         quadrant for which sin (z) = x, cos (z) = y.

cc    atanh              An option in command "variable", argument FUNCTION,
cc                         to indicate the inverse hyperbolic tangent function.
cc                         A atanh B means A * atanh (B).

cf    atanh              The inverse hyperbolic tangent function.
cf                         Example:  y = atanh (x) means y is the argument for
cf                         which the hyperbolic tangent is x, and x = tanh (y).
cf                         The range of x is -1 < x < 1.
cf
cf                         atanh (x) = 0.5 * ln ((1 + x) / (1 - x)).

cc    avg                An option in command "variable", argument FUNCTION,
cc                         to indicate the average function.
cc                         A avg B means (A + B) / 2.

cg    axial              See "axial symmetry".

cc    axial              An option in command "operator", to specify a rotation
cc                         by an angle ANGLE (counterclockwise, with the axis
cc                         pointed at the observer) around an axis VNAME.
cc                         See "planar", "serial", "triple", "vector".

cc    axial              An option in command "twist", to specify a rotation of
cc                         one or more points around an axis in proportion to
cc                         the axial distance of each point from a fixed point
cc                         on the axis.

cg    axial symmetry     Axial symmetry exists when an object may be rotated
cg                         by any amount around a particular geometric axis,
cg                         without changing shape.  Any section through the
cg                         object in a plane perpendicular to the symmetry axis
cg                         must contain only circles concentric around the axis.
cg                         Any section through the object in a plane containing
cg                         the symmetry axis must be the same for all such
cg                         planes.  See "axisymmetric".

cg    axially            See "axially symmetric".

cg    axially symmetric
cg                       See "axisymmetric".

cg    axis               See "axis of rotation", "axis of symmetry",
cg                         "principal axis".

cg    axis               An axis is a direction in 3-D space, usually associated
cg                         with a point through which the axis passes.
cg                         In Cartesian or rectangular coordinates, the major
cg                         axes are the x, y and z axes, passing through the
cg                         origin, and forming a right-hand orthogonal triple,
cg                         parallel to the thumb, first and middle fingers,
cg                         respectively.  In any other coordinate system, the
cg                         principal axes may be specified relative to the x, y
cg                         and z axes of a Cartesian or rectangular coordinate
cg                         system.
cg
cg                         A vector specifies an axis in 3-D space, if bound to
cg                         a point, or an infinite set of parallel axes, if not.
cg                         A vector and a point specify an axis in 3-D space.
cg
cg                         Any quadric surface has a symmetry with respect to
cg                         a central point, and three orthogonal axes, one, two
cg                         or three of which may be arbitrary.  The principal
cg                         axis transformation rotates these three axes, the x',
cg                         y' and z' axes, to the x, y and z axes,
cg                         and translates the central point to the origin.
cg                         The direction of the axis vector at a point on the
cg                         axis is parallel to the normal vector of the quadric
cg                         surface at that point.
cg
cg                         To find the axis associated with a scaling,
cg                         reflection or rotation operator, use command
cg                         "operator".
cg
cg                         See "transverse", "conjugate".

cc    axis               An option in command "plot", to display the plot axis
cc                         coordinates and labels [and specify the horizontal or
cc                         vertical axis coordinate and label].

cg    axis of rotation   A rotation operator OPNAME, specified with command
cg                         "operator", has associated with it an axis
cg                         and angle of rotation, which may be displayed with
cg                         command "operator OPNAME".

cg    axis of symmetry   A geometric object has an axis of symmetry if the
cg                         projection of the object in any plane through that
cg                         axis is the same.  In cylindrical coordinates, with
cg                         the z axis the axis of symmetry, the description of
cg                         the object is independent of the theta coordinate.
cg                         See "axisymmetric".

cg    axisym             See "axisymmetric", "quadric surface",
cg                         "axisym zone".

cc    axisym             In a command, means an axially symmetric quadric
cc                         surface (except in command "axisym", option "scale",
cc                         when the scaling operator is linear or radial, with
cc                         an axis not through the center of the base sphere, or
cc                         not parallel to that of the base axially symmetric
cc                         quadric surface).
cc                         Axially symmetric quadric surfaces include all types
cc                         of planes, spheres, circular cylinders, circular
cc                         cones, circular ellipsoids (oblate and prolate
cc                         spheroids), circular paraboloids, and circular
cc                         hyperboloids of one or two sheets.
cc                         See "axisymmetric", "axisym zone".

cc    axisym             Command to display or create one or more axially
cc                         symmetric quadric surfaces (except that linear or
cc                         radial scaling may create axially unsymmetric quadric
cc                         surfaces).  The normal vectors will be radially
cc                         outward.  Creating a quadric surfaces replaces any
cc                         existing quadric surface having the same name.
cc                         See "quadric" for other options.
cc                         See "do loop use".
cc
cc                         Command "axisym" relates to objects:  axisym, cone,
cc                         cylinder, ellipsoid, operator, plane, point, quadric,
cc                         sphere, symbol, variable, vector.
cc
cc                         Forms include:
cc
ccin                       help axisym
ccin                       axisym [help]
cc
cc                           Display the command options.
cc
ccin                       axisym [all,list]
cc
cc                           Display all axially symmetric quadric surfaces
cc                           (short display).
cc
ccin                       axisym list AXNAME1 AXNAME2 AXNAME3 ...
cc
cc                           Display axially symmetric quadric surfaces AXNAME1,
cc                           AXNAME2, ..., including any with the specified
cc                           names followed by one or more subscripts (short
cc                           display).
cc
ccin                       axisym AXNAME
cc
cc                           Display axially symmetric quadric surface AXNAME
cc                           (long display).
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         AXNAME or AXQ(2) to form the name by incrementing or
cc                         decrementing the base name for axially symmetric
cc                         quadric surfaces.
cc                         See command "last", "increment names".
cc
ccin                       axisym AXNAME fit PCEN VAXIS PNAME2 PNAME3
cc
cc                           Create axially symmetric quadric surface AXNAME,
cc                           centered at point PCEN, with axis vector VAXIS, and
cc                           passing through the two points PNAME2 and PNAME3.
cc
ccin                       axisym AXNAME focus PFOC VAXIS PNAME2 PNAME3
cc
cc                           Create axially symmetric quadric surface AXNAME,
cc                           with focus at point PFOC, with axis vector VAXIS,
cc                           and passing through the two points PNAME2 and
cc                           PNAME3.
cc                           See "planetary orbits".
cc
ccin                       axisym AXQ(2) move NUMAX INC AXQ(1) VMOVE
cc
cc                           Create a family of NUMAX axially symmetric quadric
cc                           surfaces AXQ(2), ..., with names incremented by INC
cc                           characters or digits, and spaced at intervals of
cc                           vector VMOVE, starting from axially symmetric
cc                           quadric AXQ(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       axisym AXQ(2) rotate NUMAX INC AXQ(1) OPNAME PINV
cc
cc                           Create a family of NUMAX axially symmetric quadric
cc                           surfaces AXQ(2), ..., with names incremented by INC
cc                           characters, by rotating the preceding axially
cc                           symmetric quadric surface with operator OPNAME and
cc                           invariant point PINV, starting from axially
cc                           symmetric quadric surface AXQ(1).
cc                           See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       axisym AXQ(2) scale NUMAX INC AXQ(1) OPNAME PINV
cc
cc                           Create a family of NUMAX quadrics AXQ(2), ..., with
cc                           names incremented by INC characters, by scaling the
cc                           preceding quadric surface with operator OPNAME and
cc                           invariant point PINV, starting from axially
cc                           symmetric quadric surface AXQ(1).
cc                           WARNING:  a linear or radial scaling axis not
cc                           parallel to that of AXQ(1) will produce axially
cc                           unsymmetric quadric surfaces; a linear or radial
cc                           scaling will change spheres to ellipsoids.
cc                           See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
cc                         Synonyms:  [help, h], [move, mv, trans, translate],
cc                         [rotate, rot].

cc    axisym             An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on an axially symmetric quadric
cc                         surface.

cg    axisym zone        A zone is axially symmetric if it is bounded by
cg                         surfaces that are all axially symmetric around the
cg                         same axis.
cg                         If all of those surfaces are planes, cylinders or
cg                         cones, the projection of the zone in a plane through
cg                         the axis is a polygon bounded entirely by straight
cg                         lines, and the volume of the zone and the area of the
cg                         projected polygon can be calculated.  See commands
cg                         "volume" and "area".  If the vertices of the polygon
cg                         are known, the bounding surfaces can be specified
cg                         with commands "plane", "cylinder" and "cone", and
cg                         the zone specified with command "zone".
cg
cg                         To find the volume of a body of revolution with a
cg                         polygonal cross section, use command "volume".

cg    axisymmetric       A surface or volume is axially symmetric if it is a
cg                         surface or body of revolution around a specified
cg                         axis, or the same for all angles around the axis.
cg                         Real quadric surfaces that are axially symmetric
cg                         include the following, in their standard forms (each
cg                         coefficient must have the preceding sign):
cg
cg                         Simple plane:                                x = 0
cg                         Coincident planes:                         x^2 = 0
cg                         Real parallel planes:            - 1 + QXX*x^2 = 0
cg                         Sphere:          - 1 + QXX * (x^2 + y^2 + z^2) = 0
cg                         Circular cylinder:     - 1 + QXX * (x^2 + y^2) = 0
cg                         Circular cone:         x^2 + y^2 - |QZZ| * z^2 = 0
cg                         Circular ellipsoid:
cg                                    - 1 + QXX * (x^2 + y^2) + QZZ * z^2 = 0
cg                         Circular paraboloid:    - |QZ| * z + x^2 + y^2 = 0
cg                         Circular hyperboloid of 1 sheet:
cg                                  - 1 + QXX * (x^2 + y^2) - |QZZ| * z^2 = 0
cg                         Circular hyperboloid of 2 sheets:
cg                                    1 + QXX * (x^2 + y^2) - |QZZ| * z^2 = 0
cg
cg                         See command "quadric".
cg
cg                         The following commands relate to
cg                         axisymmetric quadric surfaces:
cg                         accelerate, arc, axisym, cone, copy, cylinder,
cg                         debug, delete, distance, ellipsoid, extrema, help,
cg                         invert, last, list, move, operator, plane, point,
cg                         project, proximal, quadric, reflect, rename, repack,
cg                         rotate, scale, search, side, slice, sort, sphere,
cg                         symbol, synonym, tables, track, triple, vector, zone.

cg    axisymmetric arrays
cg                         Axisymmetri quadric surfaces may be created as array
cg                         with subscripted names.  See "subscript",
cg                         "subscripted names", commands "do" and "enddo".

cg    axisymmetrics      A family of axially symmetric quadric surfaces may be
cg                         created with command "axisymmetric", options "move",
cg                         "rotate" or "scale" or as follows:
cg
cg                         p pinv (options)
cg
cg                           Create an invariant point, if needed.
cg
cg                         axisym AXQ(1) (options)
cg
cg                           Create a base axially symmetric quadric surface.
cg
cg                         op opr (options)
cg
cg                           Create a tensor operator, to reflect, rotate,
cg                           invert or scale, if needed.
cg
cg                         v vmove (options)
cg
cg                           Create a vector for use as a translation operator,
cg                           if needed.
cg
cg                         cp AXQ(1) AXQ(2)
cg
cg                           Copy axially symmetric quadric surface AXQ(1) to
cg                           the first axially symmetric quadric surface.
cg
cg                         Repeat the following commands as needed:
cg
cg                         mv axisym AXQ(1) vmove
cg
cg                           Move the base axially symmetric quadric surface by
cg                           amount vmove, if needed.
cg
cg                         [inv, refl, rot, scale] axisym AXQ(1) opr [pinv]
cg
cg                           Invert, reflect, rotate or scale the base axially
cg                           symmetric quadric surface with tensor operator opr,
cg                           if needed.
cg
cg                         cp axisym AXQ(1) +
cg
cg                           Copy the base axially symmetric quadric surface to
cg                           the next axially symmetric quadric surface.

cc    AXNAME             The name of an axially symmetric quadric surface.
cc                         May have up to 24 characters, including any
cc                         subscripts, and may be ASCII, integer or floating
cc                         point.
cc                         No axially symmetric quadric name may be "+", '-',
cc                         "all", "h", "help", "list" or "thru" or begin with
cc                         "!".
cc                         May not be the same as any other quadric surface
cc                         name QNAME.  Also referred to as AXNAME1, AXNAME2,
cc                         ..., AXQ(1), AXQ(2).  Specified with command "axisym"
cc                         or "quadric".
cc
cc                         Quadric surfaces may appear in commands:
cc                         accelerate, axisym, cone, copy, cylinder, delete,
cc                         distance, ellipsoid, extrema, invert, move, name,
cc                         operator, plane, point, proximal, quadric, reflect,
cc                         rename, rotate, scale, side, slice, sphere, surface,
cc                         track, vector.
cc                         Also see commands:  last, list, repack, search, sort.

cc    AXQ(1)             In command "axisym", the name of a base axially
cc                         symmetric quadric surface, used to create a family of
cc                         axially symmetric quadric surfaces.

cc    AXQ(2)             In command "axisym", the name of the first of a family
cc                         of axially symmetric quadric surfaces to create.

cg    azimuth            The azimuth angle, theta, of a point is the angle of
cg                         the line from the origin to the point around the z
cg                         axis, measured counterclockwise from the y plane,
cg                         and limited to the range (in different applications)
cg                         from 0 to 360 degrees (0 to 2 * pi radians), or
cg                         from -180 to 180 degrees (-pi to pi radians).
cg                         See "polar", "phi".
cg
cg                         The azimuthal angle around any axis is the angle
cg                         measured in a plane perpendicular to the axis, and
cg                         counterclockwise looking in the negative direction
cg                         along the axis.  The zero point must be specified.

B-------------------------------------------------------------------------------

cg    back               See "back up".

cg    back up            There are several ways to recover from an error.
cg                         Commands may be undone or may be redone with
cg                         modified arguments.
cg                         See commands "undo", "redo", "indo".
cg                         If an object is copied before modifying it, and an
cg                         error is made in the modification, the copy may be
cg                         used to replace the original object.

cg    backslash          The backslash or escape character, "\".

cg    backup             If an object is copied before modifying it, and an
cg                         error is made in the modification, the copy may be
cg                         used to replace the original object.

cg    ballistic          See "accelerate", "trajectory".

cg    bang               The exclamation point, "!".

cg    base               An integer or non-integer floating point value may be
cg                         specified in any number base.  For value x and base
cg                         n, the digits of x are the coefficients k(m) in the
cg                         expression:
cg
cg                         x = k(m) * n^m + k(m-1) * n^(m-1) + ... + k(0) * n^0
cg                           + k(-1) * n^(-1) + k(-2) * n^(-2) + ...
cg                           + k(-j) * n^(-j)
cg
cg                         where the coefficients k(m) through k(0) define the
cg                         integer part of x, and the coefficients k(-1) through
cg                         k(-j) define the fractional part of x.
cg                         See command "base".

cg    base               See "base axisym", "base brick", "base cone",
cg                         "base cylinder", "base ellipsoid", "base line",
cg                         "base name", "base plane", "base point",
cg                         "base quadric", "base sphere", "base tetrahedron",
cg                         "base variable", "base vector", "base zone",
cg                         command "base".

cc    base               Command to convert a decimal integer or floating point
cc                         number to a specified number base.
cc                         See commands "icalc", "big", "base".
cc
cc                         Forms include:
cc
ccin                       help base
ccin                       basew [help]
cc
cc                           Display the command options.
cc
ccin                       base NBASE VALUE1 VALUE2 VALUE3 ...
cc
cc                           Convert to number base NBASE, an integer, the
cc                           decimal integer or non-integer floating point
cc                           values VALUE1, VALUE2, VALUE3, ....

cg    base axisym        A base axially symmetric quadric surface is an axially
cg                         symmetric quadric surface specified in command
cg                         "axisym", to serve as the initial axially symmetric
cg                         quadric surface for creating a family of axially
cg                         symmetric quadric surfaces translated, rotated or
cg                         scaled from the preceding axially symmetric quadric
cg                         surface.

cg    base brick         A base brick is a brick specified in command "brick",
cg                         to serve as the initial brick for creating a family
cg                         of bricks adjacent to a specified face of the
cg                         preceding brick, with thicknesses scaled from that of
cg                         the preceding brick.

cg    base cone          A base cone is a cone specified in command "cone", to
cg                         serve as the initial cone for creating a family of
cg                         cones with the same vertex and axis, but translated,
cg                         rotated or scaled from the preceding cone.

cg    base cylinder      A base cylinder is a cylinder specified with command
cg                         "cylinder", to serve as the initial cylinder for
cg                         creating a family of cylinders translated, rotated or
cg                         scaled from the preceding cylinder.

cg    base ellipsoid     A base ellipsoid is a ellipsoid specified with command
cg                         "ellipsoid", to serve as the initial ellipsoid for
cg                         creating a family of ellipsoids translated, rotated
cg                         or scaled from the preceding ellipsoid.

cg    base line          A base line is a line specified in command "line", to
cg                         serve as the initial line for creating a family of
cg                         lines with vertex point names incremented by a
cg                         specified numbers of characters from those of the
cg                         preceding line.

cg    base name          The base name for naming objects of a given type is the
cg                         last name used for creating or renaming an object of
cg                         that type, or the name specified with command "last",
cg                         whichever occurs later.  All base names may
cg                         be displayed with command "last".
cg                         The next name after or before the base name, in a
cg                         limited ASCII sequence may be used in a command to
cg                         create, copy, or rename an object of the same type,
cg                         by using the character "+" or "-" in place of the
cg                         new object name, but not in command "rename" with
cg                         option "array".
cg                         See "+", "-", "increment names", command "last".

cg    base plane         A base plane is a plane specified in command "plane",
cg                         to serve as the initial plane for creating a family
cg                         of planes at specified vector displacements, or a
cg                         family of planes rotated at specified angular
cg                         increments around an axis, or a family of planes
cg                         scaled from the preceding plane by a specified scale
cg                         factor.

cg    base point         A base point is a point specified in command "point",
cg                         to serve as the initial point for creating a family
cg                         of points translated, rotated or scaled from the
cg                         preceding point.

cg    base quadric       A base quadric surface is a quadric surface specified
cg                         with command "quadric", to serve as the initial
cg                         quadric surface for creating a family of concentric
cg                         quadric surfaces translated, rotated or scaled from
cg                         the preceding quadric surface.

cg    base sphere        A base sphere is a sphere specified in command
cg                         "sphere", to serve as the initial sphere for creating
cg                         a family of spheres rotated, scaled or translated
cg                         from the preceding sphere.

cg    base tetrahedron   A base tetrahedron is a tetrahedron specified in
cg                         command "tetrahedron", to serve as the initial
cg                         tetrahedron for creating a family of tetrahedrons
cg                         with vertex point names incremented by specified
cg                         numbers of characters from those of the preceding
cg                         tetrahedron.

cg    base variable      A base variable is a variable specified in command
cg                         "variable", to serve as the initial variable for
cg                         creating a family of variables forming a series by
cg                         incrementing and/or multiplying the preceding
cg                         variable.

cg    base vector        A base vector is a vector specified in command
cg                         "vector", to serve as the initial vector for creating
cg                         a family of vectors rotated from the preceding
cg                         vector.

cg    base zone          A base zone is a zone specified in command "zone", to
cg                         served as the initial zone for creating a family of
cg                         zones with the names of the bounding surfaces
cg                         incremented by specified numbers of characters from
cg                         those of the preceding zone.

cg    basic              See "basic commands".

cg    basic commands     See "starting up".

cg    BETA               The random variable in a relativistic Maxwellian
cg                         probability distribution function is BETA, the ratio
cg                         of the particle velocity, v, to the velocity of
cg                         light, c = 299,792,458 m / s.
cg                         A related variable is the relativistic function
cg                         GAMMA = 1 / sqrt (1 - BETA^2).
cg                         For RATIO << 1, where RATIO is the dimensionless
cg                         ratio of gas temperature to particle rest mass
cg                         energy, the expected value of BETA is approximately
cg                         1.60 * sqrt (RATIO), with a standard deviation of
cg                         approximately 0.67 * sqrt (RATIO), and the expected
cg                         value of BETA^2 is 3 * RATIO.
cg                         For RATIO >> 1, the expected value of BETA is
cg                         approximately 1 - 0.23 / RATIO^2, with a standard
cg                         deviation of approximately 1.26 / RATIO^2,
cg                         the expected value of BETA^2 is approximately
cg                         1 - 0.46 / RATIO^2, the expected value of GAMMA is
cg                         3 * RATIO, with a standard deviation of approximately
cg                         1.73 * RATIO, and the expected value of GAMMA^2 is
cg                         12 * RATIO^2.

cc    big                An option in command "debug", to display GEOM internal
cc                         parameters and variables for big integers:
cc                         abig, abigtag, idig, nbigm, ndig, ndigm.

cc    big                Command to display or create big integers, with up to
cc                         1001 digits, and with names a single capital letter
cc                         from "A" to "Z".
cc                         Big integers may be used in calculations related to
cc                         cryptography and combinatorial mathematics.
cc                         See commands "icalc" and "variable".
cc
cc                         Forms include:
cc
ccin                       help big
ccin                       big [help]
cc
cc                           Display the command options.
cc
ccin                       big all
cc
cc                           Display all big integers that are not zero.
cc
ccin                       big all zero
cc
cc                           Zero out all big integers.
cc
ccin                       big BIGNAME
cc
cc                           Display big integer BIGNAME.  BIGNAME must be a
cc                           single upper case alphabetic character, from "A" to
cc                           "Z".
cc                           Included in the display will be the one-word
cc                           integer and floating point values of BIGNAME, if
cc                           possible, and the log of BIGNAME to the base 10.
cc
ccin                       big BIGNAME [binary,octal,hex]
cc
cc                           Display big integer BIGNAME in number base
cc                           [2, 8, 16].
cc
ccin                       big BIGNAME base NBASE
cc
cc                           Display big integer BIGNAME in number base NBASE.
cc                           The stored value of BIGNAME will not be changed.
cc
ccin                       big BIGNAME = 0
cc
cc                           Set big integer BIGNAME to zero.
cc
ccin                       big BIGNAME [N|1] = INT1 INT2 INT3 ...
cc                           Replace the digits in BIGNAME, starting with the
cc                           N'th digit (N defaults to 1 if unspecifed, or if
cc                           BIGNAME is initially zero), with the digits of the
cc                           successive integer groups INT1, INT2, INT3, ...,
cc                           which may be positive integers or integer
cc                           variables, or ASCII strings containing only the
cc                           digits 0-9, but may not be the names of big
cc                           integers.  If N is not specified, BIGNAME will
cc                           initially be set to 0.
cc                           If BIGNAME is not zero, and N exceeds the initial
cc                           length of BIGNAME, all digits in between will be
cc                           zero.  Any leading zeros in BIGNAME will be
cc                           ignored.
cc
cc                           For example, the commands:
cc                             variable n = 77777
cc                             big Q = 000123 n 000456 789000
cc                           define big integer Q = 12377777000456789000
cc
ccin                       big BIGNAME tag 'BIGTAG'
cc
cc                           Give big integer BIGNAME the label or tag BIGTAG
cc                           (up to 32 characters), which may be used to define
cc                           or describe BIGNAME.  This tag will be changed by
cc                           GEOM if BIGNAME is recalculated using one of the
cc                           available functions described below.
cc
ccin                       big BIGNAME = big BIGNAME2
cc
cc                           Replace big integer BIGNAME with big integer
cc                           BIGNAME2.
cc
ccin                       big BIGNAME = INT1 [+,-,*,/] INT2
cc
cc                           Replace big integer BIGNAME with the
cc                           [sum, difference, product, quotient] of integers
cc                           INT1 and INT2, which, in this and the following
cc                           commands, may be positive integers or integer
cc                           variables or big integers.
cc                           The quotient is rounded to an integer.
cc                           See "reciprocal".
cc
cc                           Integer INT1 or INT2 or both may be the result of
cc                           multiplying a number with digits after the decimal
cc                           point by a sufficiently large power of ten to
cc                           shift the deciml point to the right of those
cc                           digits.
cc
cc                           Numbers to be added or subtracted must be
cc                           multiplied by the same power of ten.
cc                           Numbers to be multiplied may each be multiplied by
cc                           a different power of tem.
cc                           When dividing, the numerator may be multiplied by
cc                           a much larger power of ten than the denomenator,
cc                           to produce more significant figures in the result.
cc
cc                           The correct placement of the decimal point in the
cc                           result should be obvious.  If necessary, the same
cc                           calculation may be done with ordinary floating
cc                           point variables as a check.

ccin                       big BIGNAME = INT1 mod INT2
cc
cc                           Replace big integer BIGNAME with the modulus of
cc                           integer INT1 with respect to integer INT2, with
cc                           INT1 and INT2 specified as above.
cc                           This is the remainder or residual of the division
cc                           in the preceding command.
cc
ccin                       big BIGNAME = INT1 // INT2
cc
cc                           Replace big integer BIGNAME with the result of
cc                           dividing INT1 by the highest possible power of
cc                           INT2, if the latter is an exact factor of INT1.
cc
ccin                       big BIGNAME = INT1 cat INT2
cc
cc                           Replace big integer BIGNAME with the concatenation
cc                           of nonzero INT1 and nonzero INT2.
cc
ccin                       big BIGNAME = INT1 perm INT2
cc
cc                           Replace big integer BIGNAME with the number of
cc                           permutations of INT1 things taken INT2 at a time.
cc                           The largest allowed value of INT1 is 450.
cc
ccin                       big BIGNAME = INT1 comb INT2
cc
cc                           Replace big integer BIGNAME with the number of
cc                           combinations of INT1 things taken INT2 at a time.
cc                           The largest allowed value of INT1 is 450.
cc
ccin                       big BIGNAME = INT1 ^ NPOW
cc
cc                           Replace big integer BIGNAME with the NPOW'th power
cc                           of integer INT1.  If INT1 has had its decimal point
cc                           shifted N digits to the right, then BIGNAME must
cc                           have its decimal point shifted N * NPOW digits to
cc                           the left.
cc
ccin                       big BIGNAME = INT1 root NROOT
cc
cc                           Replace big integer BIGNAME with the NROOT'th root
cc                           of integer INT1, specified as above.
cc                           i.e., BIGNAME = BIGNAME2^(1/NROOT).
cc                           The root is rounded to the nearest integer.
cc                           If INT1 has had its decimal point shifted N digits
cc                           to the right, then BIGNAME must have its decimal
cc                           point shifted N / NROOT digits to the left, so
cc                           N must be an exact multiple of NROOT.
cc                                      
ccin                       big BIGNAME = INT1 fact
cc
cc                           Replace big integer BIGNAME with the factorial of
cc                           integer INT1  The largest value of INT1 that can be
cc                           used without exceeding 1001 digits is 450.
cc
ccin                       big BIGNAME = INT1 exp
cc
cc                           Replace big integer BIGNAME with the exponential
cc                           function of integer INT1.  The largest value of
cc                           INT1 that can be used without exceeding 1001 digits
cc                           is 2302.  Accuracy is to the nearest digit, but
cc                           for INT1 = 35 or more, 16 or fewer significant
cc                           figures.
cc
ccin                       big BIGNAME random N
cc
cc                           Replace big integer BIGNAME with N random digits.
cc                           The result may have leading zeros, which may be
cc                           removed by the command "big BIGNAME = 1 * BIGNAME".
cc
cc                         WARNING:  avoid conflicts between the names of
cc                         aliases and symbols and the names of big integers.
cc
cc                         Synonyms:  [help, h], [^, **], [0, zero],
cc                         [binary, bin], [octal, oct].

cg    big integer        Command "big" allows specification of up to 26 big
cg                         integers, each with up to 1001 digits, each stored
cg                         in a separate machine word.
cg                         Allowed operations include zeroing, replacement,
cg                         addition, subtraction, multiplication, division,
cg                         modulus, powers, roots, factorials, combinations,
cg                         permutations, and exponentiation.
cg                         These operations may be of use in cryptographic
cg                         applications, including encryption and decryption.
cg
cg                         The name of a big integer must be a single upper
cg                         case letter (A to Z), in order to avoid confusion
cg                         with the names of variables, symbols, aliases and
cg                         synonyms.  Each big integer is allowed to have up to
cg                         1001 digits, each stored in a separate machine word,
cg                         and in normal order, with the units digit last.
cg
cg                         The names of big integers may be incremented or
cg                         decremented by use of command "symbol", with option
cg                         "increment", or by the use of "+" or "-" in place of
cg                         the big integer name.
cg
cg                         Digits to the right of a decimal point may be
cg                         included in calculations by moving the decimal point
cg                         to the right of those digits, doing the calculations,
cg                         then deciding where to put the decimal point.
cg                         Numbers to be added or subtracted must have the
cg                         decimal point moved by equal amounts.
cg                         To find a root, multiply by a power of 10 which is
cg                         a multiple of the number of the root.

cf    big.mac            A file with 50 significant figures in the values of
cf                         pi, the golden ratio, log_e(10), log_10(ebase), and
cf                         ebase, and 21 for Euler's constant.

cc    BIGNAME            In command "big", the name of a  big integer.
cc                         Must be a single upper case letter (A to Z).
cc                         Also referred to as BIGNAME1, BIGNAME2, BIGNAME3, ...

cg    bin                A probability bin specifies the relative probability
cg                         of a discrete event or object, a discrete value of a
cg                         random variable, or a range of values of a random
cg                         variable.  In the latter case, the probability may be
cg                         a uniform, linear, power-law, exponential, normal,
cg                         relativistic Maxwellian, Planck or Wien function of
cg                         the random variable value.  A discrete object may be
cg                         any of the objects used in GEOM, including a
cg                         probability distribution function (pdf).
cg                         The maximum number of bins is now 1000.
cg
cg                         A set of probability bins may be combined to form a
cg                         probability distribution function (pdf) over a set of
cg                         discrete events, discrete values of a random
cg                         variable, or a continuous or discontinuous set of
cg                         ranges of values of a random variable.
cg
cg                         The following commands relate to bins:
cg                         bin, copy, debug, delete, help, last, list, pdf,
cg                         rename, repack, search, sort, symbol, synonym,
cg                         tables.

cc    bin                An option in command "debug", to display GEOM internal
cc                         parameters and variables for probability bins:
cc                         nbinm, nbins, abin, atypeb, probl, probr,
cc                         vranl, vranr, prbin, prbint, cosbin, conbin, vexbin,
cc                         nsampb, abins, labins.

cc    bin                Command to display one or more probability bins or to
cc                         create a probability bin.  Creating a probability bin
cc                         replaces any existing probability bin having the same
cc                         name.  All probabilities must be positive, and
cc                         the bin widths VRANR - VRANL must be positive.
cc
cc                         Command "bin" relates to objects:  bin, pdf, symbol,
cc                         variable.
cc
cc                         Forms include:
cc
ccin                       help bin
ccin                       bin [help]
cc
cc                           Display the command options.
cc
ccin                       bin [all,list]
cc
cc                           Display all bins (short display).
cc
ccin                       bin list BINAME1 BINAME2 BINAME3 ...
cc
cc                           Display bins BINAME1, BINAME2, BINAME3, ..., with
cc                           or without subscripts (short display).
cc
ccin                       bin BINAME
cc
cc                           Display bin BINAME (long display).
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         BINAME to form the name by incrementing or
cc                         decrementing the base name for probability bins.
cc                         See "base name", command "last", "increment names".
cc
ccin                       bin BINAME event [PRTOT|1]
cc
cc                           Create probability bin BINAME for a discrete event
cc                           with relative total probability PRTOT.
cc
ccin                       bin BINAME value VRAN [PRTOT|1]
cc
cc                           Create probability bin BINAME for a discrete value
cc                           VRAN of a random variable, with relative total
cc                           probability PRTOT.
cc
ccin                       bin BINAME uniform VRANL VRANR [DPR|1]
cc
cc                           Create probability bin BINAME with a uniform
cc                           differential probability DPR from value VRANL to
cc                           value VRANR of a random variable (a histogram).
cc
ccin                       bin BINAME linear VRANL VRANR [DPRL|1] [[DPRR|DPRL]]
cc
cc                           Create probability bin BINAME with linear
cc                           differential probability, from DPRL at value
cc                           VRANL, to DPRR at value VRANR of a random
cc                           variable.  DPRL defaults to 1.  DPRR defaults
cc                           to DPRL.
cc
cc                           For DPR a known function of VRAN, use the command
cc                           above between commands "do" and "enddo", with
cc                           a calculation of DPRL and DPRR for each of a range
cc                           of values of VRANL and VRANR.
cc
ccin                       bin BINAME exp VRANL VRANR SIGMA [PRTOT|1]
cc
cc                           Create probability bin BINAME with relative total
cc                           probability PRTOT, from value VRANL to value VRANR,
cc                           with exponentially varying differential
cc                           probability, with decay constant SIGMA.
cc                           For relative differential probabilities PL at VRANL
cc                           and PR at VRANR, DVAL  = VRANR - VRANL,
cc                           SIGMA = log (PL / PR) / DVAL, and
cc                           PRTOT = (PL - PR) / SIGMA.
cc                           If SIGMA = 0, PRTOT = PL * DVAL.
cc                           See "mean free path", "decay time".
cc
ccin                       bin BINAME power VRANL VRANR POW [PRTOT|1]
cc
cc                           Create probability bin BINAME with relative total
cc                           probability PRTOT, from value VRANL to value VRANR,
cc                           with power-law differential probability, with power
cc                           POW.  For relative differential probabilities PL at
cc                           VRANL and PR at VRANR,
cc                           POW = log (PR / PL) / log (VRANR / VRANL),
cc                           PRTOT = (VRANR * PR - VRANL * PL) / (POW + 1), or
cc                           if POW = -1:  PRTOT = PL * VRANL * log (PL / PR).
cc
ccin                       bin BINAME normal VMEAN DEV [PRTOT|1]
cc
cc                           Create probability bin BINAME with relative total
cc                           probability PRTOT, with a normal probability
cc                           distribution with mean value VMEAN and standard
cc                           deviation DEV.  The random variable ranges from
cc                           minus infinity to plus infinity.
cc
ccin                       bin BINAME maxwell RATIO [PRTOT|1]
cc
cc                           Create probability bin BINAME with relative total
cc                           probability PRTOT, for a relativistic Maxwellian
cc                           probability distribution, with a dimensionless
cc                           ratio RATIO of gas temperature to particle rest
cc                           mass energy.  The random variable beta is the ratio
cc                           of particle velocity to the velocity of light,
cc                           v / c, ranging from 0 to 1.  c = 299,792,458 m / s.
cc                           1 K = 8.617385E-5 eV (+/- 8.5 ppm),
cc                           1 amu = 9.3149432E8 eV (+/- 0.3 ppm).
cc
ccin                       bin BINAME [planck,wien] BTEMP [PRTOT|1]
cc
cc                           Create probability bin BINAME with relative total
cc                           probability PRTOT, with a probability distribution
cc                           of a [Planck, Wien] spectrum at temperature BTEMP.
cc                           The random variable is a frequency XNU (same units
cc                           as BTEMP) from that spectrum, ranging from 0 to
cc                           infinity.  1 K = 8.617385E-5 eV (+/- 8.5 ppm).
cc                           1 Hz = 4.1356692E-15 eV (+/- 0.3 ppm).
cc
cc                         Synonyms:  [help, h], [maxwell, Maxwell],
cc                         [normal, norm], [planck, Planck], [power, pow],
cc                         [wien, Wien].

cc    bin                An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on one or more bins.

cc    bin                A synonym for binary in commands "icalc", "big".

cg    bin arrays         Bins may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    bin types          The types of probability bins currently include:
cg
cg                         Type                               Key word
cg
cg                         discrete event                     event
cg                         discrete value                     value
cg                         uniform distribution (histogram)   uniform
cg                         linear distribution                linear
cg                         power-law distribution             power,   pow
cg                         exponential distribution           exp
cg                         normal (Gaussian) distribution     normal,  norm
cg                         relativistic Maxwellian spectrum   maxwell, Maxwell
cg                         Planck spectrum                    planck,  Planck
cg                         Wien spectrum                      wien,    Wien

cc    BINAME             The name of a probability bin.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.
cc                         No bin name may be "+", "-", "all", "h", "help",
cc                         "list" or "thru", begin with "!" or contain ";".
cc                         Specified with command "bin".
cc                         Also referred to as BINAME1, BINAME2, BINAME3, ...
cc
cc                         Probability bins may appear in commands:
cc                         bin, copy, delete, rename, pdf.
cc                         Also see commands:  last, list, repack, search, sort.

cc    binary             An option in command "big", to display a big integer
cc                         in binary.

cc    binary             An option in command "icalc", to turn on the binary
cc                         mode display of the results.
cc                         Synonyms:  [binary, bin].

cg    binary             The binary form of an integer M, specified in the
cg                         current integer mode (see commands "icalc", "big"),
cg                         may be displayed with commands:
cg
cg                         icalc binary
cg
cg                           Turn on display of results of command "icalc" in
cg                           binary mode.
cg
cg                         binary BIGNAME binary
cg
cg                           Display big integer BIGNAME in number base 2.
cg
cg                         icalc M
cg
cg                           Specify integer M in the current integer mode, and
cg                           display M in decimal, hexadecimal, octal and binary
cg                           mode.

cg    bisect             To find the bisector of an angle, use command "bisect".
cg
cg                         To find the midpoint of a line between two points,
cg                         PNAME1 and PNAME2:
cg
cg                         vector VNAME = PNAME1 PNAME2
cg
cg                           Create the vector from point PNAME1 to point
cg                           PNAME2.
cg
cg                         copy p PNAME1 PMID
cg
cg                           Create a point PMID at PNAME1.
cg
cg                         move p PMID VNAME 0.5
cg
cg                           Move point PMID to the midpoint.  To create a plane
cg                           at the midpoint, perpendicular to the line from
cg                           point PNAME1 to PNAME2:
cg
cg                         pl PLNAME v PMID VNAME
cg
cg                           Create a plane at the midpoint, with a normal
cg                           vector parallel to the line from point PNAME1 to
cg                           point PNAME2.
cg
cg                         To find one of the two planes bisecting the space
cg                         between two other planes, use command "distance" to
cg                         find the intersection of the two planes, then use
cg                         command "plane" to create a plane through a point on
cg                         the line of intersection, with a normal vector equal
cg                         to either the sum or the difference of the normal
cg                         vectors of the two planes.  The command "vector",
cg                         with option "sum", may used to find that sum or
cg                         difference.

cc    bisect             Command to bisect the angle formed by the lines
cc                         connecting three points.
cc
cc                         Command "bisect" relates to objects:  point, symbol.
cc
cc                         Forms include:
cc
ccin                       help bisect
ccin                       bisect [help]
cc                           Display the command options.
cc
ccin                       bisect PNAME1 PNAME2 PNAME3
cc
cc                           Find the bisector of the angle formed by the three
cc                           points PNAME1, PNAME2 and PNAME3, and display the
cc                           intercept of the bisector on the line joining
cc                           points PNAME3 and PNAME1, the vector from point
cc                           PNAME2 to the intercept and the length of that
cc                           vector.
cc
cc                         Synonyms:  [help, h].

cg    bisector           The perpendicular bisectors of the three edges of a
cg                         triangle meet at the center of the circumscribed
cg                         circle.  The bisectors of the three vertex angles of
cg                         a triangle meet at the center of the inscribed
cg                         circle.  See "altitude", "median", "trig".

cc    bl                 A synonym for block.

cg    blackjack          See "21".

cg    blank              The initial field delimiter is a blank character,
cg                         but may be changed with command "delimiter".
cg                         If the field delimiter is a blank character, any
cg                         number of leading and trailing blank characters will
cg                         be ignored, and multiple blank characters between
cg                         words are treated as a single field delimiter.

cg    blank              See "blank line".

cg    blank line         Blank input lines will be ignored.

cg    block              See "mesh block".

cc    block              An option in commands "mesh" and "cluster", to operate
cc                         on a specified mesh block.
cc                         Synonyms:  [block, bl].

cg    Boolean            Boolean operations are on individual bits of one or
cg                         two machine words.  For each bit or pair of bits,
cg                         the various Boolean operations available with
cg                         commands "icalc" and "cluster", return the following
cg                         results:
cg
cg                           Bit A:                   | 0     0     1     1
cg                           Bit B:                   | 0     1     0     1
cg                           -------------------------|--------------------
cg                              comp. A (complement)  | 1     1     0     0
cg                              comp. B (complement)  | 1     0     1     0
cg                           -------------------------|--------------------
cg                           A .not.  B (not)         | 0     0     1     0
cg                           B .not.  A (not)         | 0     1     0     0
cg                           -------------------------|--------------------
cg                           A .and.  B (intersection)| 0     0     0     1
cg                           A .nand. B (comp. .and.) | 1     1     1     0
cg                           -------------------------|--------------------
cg                           A .or.   B (union)       | 0     1     1     1
cg                           A .nor.  B (comp. .or.)  | 1     0     0     0
cg                           -------------------------|--------------------
cg                           A .xor.  B (exclusive or)| 0     1     1     0
cg                           A .xnor. B (comp. .xor.) | 1     0     0     1
cg                           ----------------------------------------------
cg
cg                         To do Boolean operations on clusters of points, see
cg                         command "cluster".
cg
cg                         To do Boolean operations on machine words, see
cg                         command "icalc".

cg    bound              See "bound point".

cg    bound point        The point in 3-D space at which a vector is specified.
cg                         Required for converting vectors between rectangular,
cg                         cylindrical and spherical coordinates.  It is only in
cg                         rectangular coordinates that the components of all
cg                         parallel vectors of the same magnitude are equal.
cg                         May be specified with command "vector VNAME  = ... ",
cg                         and changed with command "vector VNAME bound PNAME".
cg                         See "coordinate conversion", "vector conversion".

cc    box                An option in command "sudoku", to assign up to 9
cc                         digits to a 3 x 3 Sudoku box.

cg    box                To create a zone with the shape of a box, or a right
cg                         parallelepiped, use commands "plane" and "zone", or
cg                         command "brick".

cc    br                 A synonym for brick.

cg    brick              See "brick (cylindrical)", "brick (rectangular)",
cg                         "brick (spherical)".

cg    brick              A brick is a six-faced solid geometric object in 3-D
cg                         space, bounded by three specified pairs of coordinate
cg                         surfaces, one pair for each of the three coordinates
cg                         (u, v, w) of a specified orthogonal coordinate
cg                         system, with angles measured in specified units.
cg                         See "coordinate", "angles".
cg                         A brick has 8 vertices, 12 edges, and 6 faces.
cg                         The maximum number of bricks is now 1000.
cg                         See "briquette".
cg
cg                         If one pair of coordinates are equal, the brick is
cg                         a plane, or a section of a circular cylinder, sphere
cg                         or circular cone, and has zero volume.
cg                         See "tile", "sheet".
cg
cg                         If two pairs of coordinates are equal, the brick is
cg                         a line segment or an arc of a circle, and has zero
cg                         volume and zero areas on the faces.  See "filament".
cg
cg                         If all three pairs of coordinates are equal, the
cg                         brick is a point, and has zero volume, zero areas on
cg                         the faces, and zero edge lengths.
cg
cg                         A brick is a convenient object for use in specifying
cg                         a limited geometric region for carrying out other
cg                         geometric operations.  See commands "mcvol", "point",
cg                         "plot".
cg
cg                         To create and assign mesh points uniformly
cg                         distributed within a brick, use command
cg                         "point PMESH brick BRNAME mesh block [volume]".
cg
cg                         See "zone (rectangular)", "zone (cylindrical)",
cg                         "zone (spherical)".
cg                         See "x plane", "y plane", "z plane", "rcyl cylinder",
cg                         "rsph sphere", "theta plane", "phi cone".
cg
cg                         To create a brick containing a set of points,
cg                         first create a cluster of the points, and then use
cg                         the displayed minimum and maximum coordinates to
cg                         create the brick.
cg
cg                         To find if a point is in a brick, use command
cg                         "distance" or "where".
cg
cg                         To find the distances from a point to the six
cg                         surfaces bounding a brick, use command "distance".
cg
cg                         To create a family of vertex points, distributed over
cg                         the u, v and w coordinate surfaces so as to divide a
cg                         brick BRNAME up into equal volume elements, each with
cg                         6 faces, 12 edges and 8 vertex points, use command:
cg                         "point PMESH brick BRNAME mesh block volume".
cg
cg                         The following commands relate to bricks:
cg                         brick, cluster, copy, debug, delete, distance, help,
cg                         last, list, mcvol, point, rename, repack, search,
cg                         sort, symbol, synonym, tables, where.

cc    brick              An option in command "debug", to display GEOM internal
cc                         parameters and variables for bricks:  nbrickm,
cc                         nbricks, abrick, asysbr, angbr, ubr, dubr, vbr, dvbr,
cc                         wbr, dwbr, volbr, abricks, labricks.
cc                         Synonyms:  [brick, br].

cc    brick              An option in command "point", to create a family of
cc                         points in a brick, at equal-volume values between
cc                         the minimum and maximum u, v and w coordinates of
cc                         the brick, each with a unique name.

cc    brick              An option in commands "cluster", "copy", "delete",
cc                         "last", "list", "rename", "repack" and "sort", to
cc                         perform the specified operation on one or more
cc                         bricks.
cc                         Synonyms:  [brick, br].

cc    brick              Command to display or create bricks.  Creating a brick
cc                         replaces any existing brick having the same name.
cc                         The display for a brick includes the coordinate
cc                         system, the angle units, the minimum, increment and
cc                         maximum values of the coordinates of the bounding
cc                         surfaces in each of the three coordinate directions,
cc                         the edge lengths, the face areas, and the volume.
cc                         See "do loop use".
cc
cc                         Command "brick" relates to objects:  brick, symbol,
cc                         variable.
cc
cc                         Forms include:
cc
ccin                       help brick
ccin                       brick [help]
cc
cc                           Display the command options.
cc
ccin                       brick [all,list]
cc
cc                           Display all bricks (short display).
cc
ccin                       brick list BRNAME1 BRNAME2 BRNAME3 ...
cc
cc                           Display bricks BRNAME1, BRNAME2, BRNAME3, ...,
cc                           with or without subscripts (short display).
cc
ccin                       brick BRNAME
cc
cc                           Display brick BRNAME (long display).
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         BRNAME or BR(2) to form the name by incrementing or
cc                         decrementing the base name for bricks.
cc                         See command "last", "increment names".
cc
ccin                       brick BRNAME = UMIN UMAX VMIN VMAX WMIN WMAX
cc
cc                           Create brick BRNAME, bounded by the coordinate
cc                           surfaces at UMIN and UMAX, VMIN and VMAX, WMIN and
cc                           WMAX, in the current coordinate system (u, v, w),
cc                           which may be rectangular (x, y, z), cylindrical
cc                           (rcyl, theta, z) or spherical (rsph, theta, phi),
cc                           with the current units for angles (degrees or
cc                           radians).  One, two or three of the coordinate
cc                           pairs may be equal, to create a surface, a segment
cc                           of a line or arc of a circle, or a point, resp.
cc                           This command could be inside a triple do loop
cc                           over the U, V and W indices, to create a family
cc                           of bricks.
cc
ccin                       brick BR(2) incr NUMBR INC BR(1) [-] CDIR [FMULT|1]
cc
cc                           Create a family of NUMBR bricks BR(2), ..., with
cc                           names incremented by INC characters, each sharing
cc                           a coordinate surface in the [negative] coordinate
cc                           direction CDIR (x, y, z, rcyl, theta, rsph, phi),
cc                           with the preceding brick, starting from brick
cc                           BR(1), and with a thickness in direction CDIR equal
cc                           to FMULT times the thickness of the preceding
cc                           brick.  See "increment names".
cc
cc                           This command can be replaced by using commands
cc                           "do" and "enddo", with any of the "brick" commands,
cc                           to create a do loop over bricks with subscripted
cc                           names, with more general variation of properties.
cc                           For example, creating a family of bricks with
cc                           constant thickness increments in the U direction:
cc
cc                           variable UMIN    = UMINVAL
cc                           variable UMAX    = UMAXVAL
cc                           variable UTHICK  = UMAX - UMIN
cc                           variable NB      = NBINIT
cc                           brick BRNAME(NB) = UMIN UMAX VMIN VMAX WMIN WMAX
cc                           do n = 1 NUMBR
cc                             variable NB      = NB + INC
cc                             variable UMIN    = UMAX
cc                             variable UMAX    = UMAX + UTHICK
cc                             brick BRNAME(NB) = UMIN UMAX VMIN VMAX WMIN WMAX
cc                           enddo
cc
cc                         Synonyms:  [brick, br], [help, h], [increment, incr].

cg    brick (cylindrical)
cg                         A brick defined in cylindrical coordinates, bounded
cg                         by RCYLMIN, RCYLMAX, THETAMIN, THETAMAX, ZMIN and
cg                         ZMAX has the bounding surfaces:
cg                           -RCYLMIN + x^2 + y^2 = 0
cg                           -RCYLMAX + x^2 + y^2 = 0
cg                           sin (THETAMIN) * x - cos (THETAMIN) * y = 0
cg                           sin (THETAMAX) * x - cos (THETAMAX) * y = 0
cg                           -ZMIN + z = 0
cg                           -ZMAX + z = 0
cg
cg                         The distances D from a point P1 = (X1, Y1, Z1) to
cg                         each of these surfaces are:
cg                           D = RCYLMIN - sqrt (X1^2 + Y1^2)
cg                           D = RCYLMAX - sqrt (X1^2 + Y1^2)
cg                           D = sin (THETAMIN) * X1 - cos (THETAMIN) * Y1
cg                           D = sin (THETAMAX) * X1 - cos (THETAMAX) * Y1
cg                           D = ZMIN - Z1
cg                           D = ZMAX - Z1
cg
cg                         If P1 = (RCYL, THETA, Z1), substitute
cg                           X1 = RCYL * cos (THETA)
cg                           Y1 = RCYL * sin (THETA)
cg                           sqrt (X1^2 + Y1^) = RCYL
cg
cg                         See "proximal".

cg    brick (rectangular)
cg                         A brick defined in rectangular coordinates, bounded
cg                         by XMIN, XMAX, YMIN, YMAX, ZMIN and ZMAX has the
cg                         bounding planes:
cg                           -XMIN + x = 0      -XMAX + x = 0
cg                           -YMIN + y = 0      -YMAX + y = 0
cg                           -ZMIN + z = 0      -ZMAX + z = 0
cg
cg                         The distances D from a point P1 = (X1, Y1, Z1) to
cg                         each of these planes are:
cg                           D = XMIN - X1      D = XMAX - X1
cg                           D = YMIN - Y1      D = YMAX - Y1
cg                           D = ZMIN - Z1      D = ZMAX - Z1
cg
cg                         See "proximal".

cg    brick (spherical)
cg                       A brick defined in spherical coordinates, bounded by
cg                         RSPHMIN, RSPHMAX, THETAMIN, THETAMAX, PHIMIN and
cg                         PHIMAX has the bounding surfaces:
cg                           -RSPHMIN + x^2 + y^2 + z^2 = 0
cg                           -RSPHMAX + x^2 + y^2 + z^2 = 0
cg                           sin (THETAMIN) * x - cos (THETAMIN) * y = 0
cg                           sin (THETAMAX) * x - cos (THETAMAX) * y = 0
cg                           (cos (PHIMIN))^2 * (x^2 + y^2) -
cg                             (sin (PHIMIN))^2 * z^2 = 0
cg                           (cos (PHIMAX))^2 * (x^2 + y^2) -
cg                             (sin (PHIMAX))^2 * z^2 = 0
cg
cg                         The distances D from a point P1 = (X1, Y1, Z1) to
cg                         each of these surfaces are:
cg                           D = RSPHMIN - sqrt (X1^2 + Y1^2 + Z1^2)
cg                           D = RSPHMAX - sqrt (X1^2 + Y1^2 + Z1^2)
cg                           D = sin (THETAMIN) * X1 - cos (THETAMIN) * Y1
cg                           D = sin (THETAMAX) * X1 - cos (THETAMAX) * Y1
cg                           D = -sqrt (X1^2 + Y1^2) * cos (PHIMIN) +
cg                               abs (Z1) * sin (PHIMIN)
cg                           D = -sqrt (X1^2 + Y1^2) * cos (PHIMAX) +
cg                               abs (Z1) * sin (PHIMAX)
cg
cg                         If P1 = (RSPH, THETA, PHI), substitute
cg                           X1 = RSPH * sin (PHI) * cos (THETA)
cg                           Y1 = RSPH * sin (PHI) * sin (THETA)
cg                           Z1 = RSPH * cos (PHI)
cg                           sqrt (X1^2 + Y1^2 + Z1^2) = RSPH
cg
cg                         See "proximal".

cg    brick arrays       Bricks may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    bricks             A family of bricks may be created with command "brick",
cg                         option "increment".

cg    briquette          A briquette is a small volume element of a brick,
cg                         bounded by six coordinate surfaces through eight
cg                         vertex points created by command
cg                         "point PMESH brick BRNAME mesh block volume".
cg                         All such briquettes have equal volume.

cc    BRNAME             The name of a brick.  May have up to 24 characters,
cc                         including any subscripts, and may be ASCII, integer
cc                         or floating point.
cc                         No brick name may be "+", "-", "all", "h", "help",
cc                         "list" or "thru", begin with "!" or contain ";".
cc                         Specified with command "brick".
cc                         Also referred to as BRNAME1, BRNAME2, BRNAME3, ...
cc                         BR(1), BR(2), ...
cc
cc                         Bricks may appear in commands:
cc                         brick, copy, delete, mcvol, plot, point, rename,
cc                         where.
cc                         Also see commands:  last, list, repack, search, sort.

cc    BTEMP              In command "bin", the black-body temperature of a
cc                         Planck or Wien spectrum.

C-------------------------------------------------------------------------------

cc    C                  A synonym for c in a comment line.

cc    C                  In command "delimiter", a character to be used as a
cc                         field delimiter, which must be one of the following:
cc                         (blank) (  )  ,  :  <  >  [  \  ]  ^  _  `  {  |  }

cg    C                  The musical note middle C has a frequency of
cg                         523.2511306012 Hz on an equally-tempered scale.

cc    c                  A synonym for command in command "input".

cc    c                  The first word of a comment line.
cc                         See "!", "#", "*", "/".
cc                         Synonyms: [c, C, c...., C...., c++++, C++++, c----,
cc                         C----, c____, C___, !].

cc    C++++              A synonym for c++++ in a comment line.

cc    c++++              A synonym for c.

cc    C----              A synonym for c---- in a comment line.

cc    c----              A synonym for c.

cc    C....              A synonym for c.... in a comment line.

cc    c....              A synonym for c.

cg    C1                 See "C1, C2, ...".

cc    C1, C2, ...        In command "contfr", coefficients of a continued
cc                         fraction.

cg    C2                 See "C1, C2, ...".

cg    calculate          To do simple calculations with real numbers, use
cg                         command "variable".
cg                         To do simple calculations with integers, in decimal,
cg                         hexadecimal or octal mode, use command "icalc".
cg                         To do simple calculations with big integers, use
cg                         command "big".

cc    call               A synonym for input.

cg    calls              For subroutine calls, see files geom_link, geom_to,
cg                         geom_from, geom_aptcomms, geom_commapts.

cn    card.mac           An input file that sets up probability bins and a
cn                         pdf representing a deck of playing cards, to
cn                         demonstrate how to work with bins and pdfs.

cc    cart               A synonym for cartesian.

cc    Cartesian          A synonym for cartesian.

cg    Cartesian          A 3-D coordinate system using the coordinates
cg                         (x, y, z).  A rectangular coordinate system.
cg                         To create a volume element bounded by surfaces of a
cg                         rectangular coordinate system, use command "brick".
cg                         To create zones partially or completely bounded by
cg                         planar surfaces, use command "plane", options
cg                         "parallel", "move", "rotate", "scale", and
cg                         command "zone".
cg
cg                         To use a Cartesian coordinate system (the default),
cg                         use command:
cg
cg                         coord rect
cg
cg                           Make the coordinate system Cartesian.

cc    cartesian          An option in command "coordinate", to use a 3-D
cc                         Cartesian coordinate system with x, y and z
cc                         coordinates.
cc                         Synonyms:  [cartesian, cart, Cartesian,
cc                         rectangular, rect, xyz].

cg    case               The case of command arguments displayed in geom_base,
cg                         and in the "help" messages in GEOM, are lower case
cg                         for arguments to be typed literally as shown, and
cg                         UPPER CASE for arguments that are to be provided by
cg                         the user.  Arguments provided by the user
cg                         may be either ASCII strings (using any case or
cg                         mixture of cases), explicit numerical values,
cg                         variables or symbols.
cg                         See commands "alias", "symbol", "variable".

cc    cat                An option in command "big", to create a big integer by
cc                         concatenating two nonzero big integers, making it
cc                         easy to add digits at the beginning or end of a big
cc                         integer.

cc    CC                 A synonym for cc in a comment line.

cc    cc                 In columns 1-2, the first two characters of a
cc                         comment line.
cc                         Synonyms: [cc, CC].

cg    cc                 In columns 1-2 of geom_base, indicates a description of
cg                         a command or a description of a word that is part of
cg                         a command.

cg    ccin               In columns 1-4 of geom_base, indicates a command.

cg    cd                 In columns 1-2 of geom_base, indicates a directory.

cg    cell               An option in command "sudoku" to assign a digit to
cg                         a cell, then to display all of the digits permitted
cg                         in each cell.

cg    cen                Indicates the center of a geometric object.
cg                         In a brick, the centroid or center of volume.

cg    center             The center of a quadric surface is its center of
cg                         symmetry.  To move the center of a quadric surface of
cg                         type QTYPE (plane, sphere, cylinder, cone, hyperb,
cg                          ellipse, axisym, quadric), with name
cg                         QNAME, to the origin, execute the following:
cg
cg                         point pcen QTYPE QNAME
cg
cg                           Create point pcen, the center of QNAME.
cg
cg                         vector vmove QTYPE QNAME
cg
cg                           Create vector vmove, pointing from the center of
cg                           QNAME to the origin.
cg
cg                         move QTYPE QNAME vmove
cg
cg                           Translate QNAME to the origin.  QTYPE may be
cg                           "quadric" for all types of simple planes and
cg                           quadric surfaces.
cg
cg                         move point pcen vmove
cg
cg                           Check the translation.  The new pcen should be at
cg                           the origin.
cg
cg                         Vector vmove may also be used for the reverse
cg                         translation.
cg
cg                         See "align".
cg
cg                         Argument PCEN is the name of a point at the center of
cg                         an annular disk, quadric surface, regular polygon or
cg                         a regular polyhedron.  See commands "axisym", "disk",
cg                         "ellipsoid", "polygon", "polyhedron", "project",
cg                         "sphere".

cg    central            See "angle, central".

cg    centroid           In a brick, a point at the center of volume of the
cg                         brick.  Also refers to the distances through the
cg                         brick in the coordinate directions at the centroid,
cg                         and the areas of the coordinate surfaces through the
cg                         centroid.

cg    centroid           When a triangle is created or displayed, the centroid
cg                         is displayed.  The coordinates of the centroid are
cg                         the average of the coordinates of the vertices.
cg                         The centroid is at the intersection of the
cg                         medians, the lines from each vertex to the midpoint
cg                         of the opposite edge.
cg                         See "circumscribed circle", "inscribed circle",
cg                         "orthocenter", commands "triangle", "trig".

cg    cents              A logarithmic measure of musical pitches, 1200 to an
cg                         octave.  100 cents corresponds to a semitone on an
cg                         equally-tempered scale.  The difference between two
cg                         frequencies F1 and F2 in cents is given by:
cg                           cents = 1200 * log (F1/F2) / log (2).
cg                         See "equally-tempered".

cc    cf                 A synonym for contfr.

cg    cf                 In columns 1-2 of geom_base, indicates a function.

cc    CFNAME1            An option in command "quadric", to specify a new value
cc                         CFVAL1 of an individual coefficient in the general
cc                         implicit equation of a specified quadric surface.
cc                         May be QC, QX, QY, QZ, QXY, QYZ, QZX, QXX, QYY or
cc                         QZZ.  Likewise for CFNAME2, CFNAME3, ...

cc    CFVAL1             A new value of coefficient CFNAME1 in the general
cc                         implicit equation of a specified quadric surface.
cc                         Likewise for CFVAL2, CFVAL3, ...

cg    cg                 In columns 1-2 of geom_base, indicates a general
cg                         definition.

cg    chance             See "probability", "flip a coin", "spin the bottle".

cg    change             See "change name".

cg    change name        To change the name of an object, or an array of
cg                         objects, use command "rename".

cg    changes            To repeat a GEOM run with changes, make a new input
cg                         file from the output file from the GEOM run.
cg                         See "input file".

cg    character          A character is a single ASCII 8-bit symbol, included in
cg                        the ASCII character set.  See "character set".

cg    character          See "character data", "character set".

cg    character data     Character data is data which has been assigned type
cg                         character in GEOM, with a specified number of
cg                         characters.  On execution, GEOM fills all such data
cg                         with blanks.  See "data types".

cg    character set      The available keyboard character set on the systems
cg                         that GEOM is currently running on includes the
cg                         ASCII characters:
cg
cg                         (blank)  !  "  #  $  %  &  '  (  )    *  +  ,  -
cg                         .  /   0-9  :  ;  <  =  >  ?  @  A-Z  [  \  ]  ^
cg                         _  `   a-z  {  |  }  ~
cg
cg                         Other characters may be obtained with the <Alt>
cg                         or <Ctrl> keys, but may produce unexpected results.
cg
cg                         The inline function char(n) equals the characters:
cg
cg                         char(0)   =  (null)
cg
cg                         char(1)     to   char(31)  =  (control)
cg
cg                         char(32)  =  (blank)              char(33)  =  !
cg                         char(34)  =  "   char(35)  =  #   char(36)  =  $
cg                         char(37)  =  %   char(38)  =  &   char(39)  =  '
cg                         char(40)  =  (   char(41)  =  )   char(42)  =  *
cg                         char(43)  =  +   char(44)  =  ,   char(45)  =  -
cg                         char(46)  =  .   char(47)  =  /
cg
cg                         char(48)    to   char(57)  =  0-9
cg
cg                         char(58)  =  :   char(59)  =  ;   char(60)  =  <
cg                         char(61)  =  =   char(62)  =  >   char(63)  =  ?
cg                         char(64)  =  @
cg
cg                         char(65)    to   char(90)  =  A-Z
cg
cg                         char(91)  =  [   char(92)  =  \   char(93)  =  ]
cg                         char(94)  =  ^   char(95)  =  _   char(96)  =  `
cg
cg                         char(97)    to   char(122) =  a-z
cg
cg                         char(123) =  {   char(124) =  |   char(125) =  }
cg                         char(126) =  ~
cg
cg                         char(127) =  (control)
cg
cg                         char(128)   to   char(255) =  (non-ASCII)

cg    characteristics    Each type of quadric surface has certain unique
cg                         characteristics, which are displayed when the
cg                         quadric surface is displayed.  These include:
cg
cg                         alignment:  all types;
cg                         axis intercepts:  all types;
cg                         axially symmetry:  all types;
cg                         center(s) of symmetry:  all types;
cg                         coefficients of implicit equation:  all types;
cg                         distance between planes:  parallel planes;
cg                         eccentricity:  hyperbolic and elliptic cylinders,
cg                           hyperboloids of one or two sheets, ellipsoids;
cg                         extrema:  all types;
cg                         foci:  parabolic, hyperbolic and elliptic cylinders,
cg                           paraboloids, hyperboloids, ellipsoids;
cg                         general type:  all types;
cg                         half-angles:  intersecting planes, cones, hyperbolic
cg                           cylinders and hyperboloids;
cg                         invariants:  all types;
cg                         latus rectum:  parabolic and hyperbolic cylinders,
cg                           circular and elliptic paraboloids, hyperboloids;
cg                         normal vector:  simple planes;
cg                         plane type:  simple planes;
cg                         radius, circumference and circular area:
cg                           circular cylinders, spheres;
cg                         rotation tensor to align the major axes with the
cg                           coordinate axes:  all types;
cg                         semiaxes:  elliptic cylinders, ellipsoids;
cg                         simple planes:  coincident planes, parallel planes
cg                           and intersecting planes;
cg                         surface area:  sphere;
cg                         symmetry axis vectors:  all types;
cg                         transverse and conjugate semiaxes:
cg                           hyperbolic cylinders,
cg                           hyperboloids of one or two sheets;
cg                         vertex to focus distance:  parabolic cylinders.
cg                           circular paraboloids;
cg                         volume:  ellipsoid, sphere.

cg    charge             To find the machine time charged to the problem, use
cg                         command "time".

cg    chi.group.mac      A command file for finding the number of ways to select
cg                         two or more groups of items with specified lengths
cg                         from an anagram of all the items in those groups,
cg                         when the sequence of items in each group is unchanged
cg                         in the anagram.  See "chimera"

cg    chimera            An anagram of two or more groups of items, with the
cg                         sequence of items in each group unchanged in the
cg                         anagram.  See "chi.group.mac".

cg    Chimera Puzzle     A word puzzle, in which a chimera is give, and the
cg                         puzzle solver must find the phrase for which the
cg                         chimera is an anagram in which the sequence of
cg                         letters in each word of the phrase is unchanged.
cg                         See "chimera", test problem "chi.test", command file
cg                         "chi.group.mac".

cg    Chinese            See "Chinese Remainder".

cg    Chinese Remainder
cg                       The Chinese Remainder Theorem tells how to find the
cg                         least integer that has a specified set of remainders,
cg                         when divided by a specified set of divisors:
cg
cg                           REM1 = mod (I, IDIV1)
cg                           REM2 = mod (I, IDIV2)
cg                           REM3 = mod (I, IDIV3)
cg                           ...
cg                           REMN = mod (I, IDIVN)
cg
cg                         No pair of divisors may have a common factor, which
cg                         is easily satisfied with only prime divisors.
cg
cg                         Let IP = IDIV1 * IDIV2 * IDIV3 * ... * IDIVN.
cg                         There is a unique solution I (modulo IP), found as
cg                         follows:
cg
cg                         Let M1 = IP / IDIV1
cg                         Let M2 = IP / IDIV2
cg                             ...
cg                         Let MN = IP / IDIVN
cg
cg                         Let K1 be defined such that K1*M1 mod IDIV1 = 1
cg                             K1 = mod (M1^(IDIV1 - 2), IDIV1)
cg
cg                         Let K2 be defined such that K2*M2 mod IDIV2 = 1
cg                             K2 = mod (M2^(IDIV2 - 2), IDIV2)
cg                             ...
cg                         Let KN be defined such that KN*MN mod IDIVN = 1
cg                             KN = mod (MN^(IDIVN - 2), IDIVN)
cg
cg                         The K1, K2, ..., KN values may also be found just by
cg                         trying all of the integers until one works.
cg                         This avoids generating very large integers, as may
cg                         happen using the equations above.
cg
cg                         Then the solution is given by:
cg
cg                           I = K1*M1*IREM1 + K2*M2*IREM2 + ... + KN*MN*IREMN
cg                           I (minimum) = mod (I, IP)
cg
cg                         Other larger solutions are I + K * IP, where K is
cg                         any positive integer.
cg
cg                         See command "crt".
cg    choose randomly    See commands "bin", "pdf", "sample".
cg                         See "spin the bottle".

cc    circ               A synonym for circle.

cg    circle             A circle is a curve in a plane, everywhere equidistant
cg                         from a central point.  For a radius R, the
cg                         circumference is 2 * pi * R, and the area is
cg                         pi * R^2.
cg                         To find a circle through three points, use command
cg                         "circle".
cg                         To find two circles, each tangent to three mutually
cg                         tangent circles with specified radii, use command
cg                         "kiss".  See "tangent circles".
cg                         To find any intersection between two circles, use
cg                         command "intcirc".
cg                         To find the circular intersection between a plane
cg                         and a sphere or between two spheres, use command
cg                         "distance".

cc    circle             Command to find a circle through three specified
cc                         points or to find two circles each tangent to three
cc                         tangent circles with specified radii.
cc
cc                         Command "circle" relates to objects:  point, symbol.
cc
cc                         Forms include:
cc
ccin                       help circle
ccin                       circle [help]
cc
cc                           Display the command options.
cc
ccin                       circle point PNAME1 PNAME2 PNAME3
cc
cc                           Find the circle through the three points PNAME1,
cc                           PNAME2 and PNAME3, and display the radius, center,
cc                           unit normal vector, and area.
cc
cc                         Use command "disk" to create circular or annular
cc                         disks representing the circles.  Use command
cc                         "cylinder" to create cylinders parallel to the z
cc                         axis and through the circles.
cc                         Use commands "move" and "rotate", to move and orient
cc                         the disks or cylinders anywhere in 3-D space.
cc                         Use command "kiss" to find the center coordinates
cc                         of three tangent circles with specified radii, and
cc                         the radii and center coordinates of two additional
cc                         circles tangent to the first three.
cc
cc                         Synonyms:  [circle, circ], [help, h].

cg    circular           See "circular cone", "circular cylinder",
cg                         "circular ellipsoid", "circular paraboloid".

cg    circular cone      A circular cone is an axially symmetric quadric surface
cg                         for which the standard equation is:
cg                           x^2 + y^2 - |QZZ|*z^2 = 0  (QZZ < 0),
cg                         An imaginary circular cone is a quadric surface for
cg                         which the standard equation is:
cg                           x^2 + y^2 + QZZ*z^2 = 0,       (QZZ > 0).
cg                         This last equation is also satisfied at the real
cg                         point (0,0,0).

cg    circular cylinder
cg                       A circular cylinder is an axially symmetric quadric
cg                         surface for which the standard equation is:
cg                          - 1 + QXX * (x^2 + y^2) = 0
cg                         An imaginary circular cylinder is a quadric surface
cg                         for which the standard equation is:
cg                            1 + QXX * (x^2 + y^2) = 0,     (QXX > 0).

cg    circular ellipsoid
cg                       A circular ellipsoid is an axially symmetric quadric
cg                         surface for which the standard equation is:
cg                          - 1 + QXX*x^2 + QYY*y^2 + QZZ*z^2 = 0,
cg                           (QXX => QYY => QZZ > 0),
cg                         with two of the coefficients QXX, QYY, QZZ equal.
cg
cg                         A circular ellipsoid may be either an oblate spheroid
cg                         (QYY = QZZ) or a prolate spheroid (QXX = QYY).

cg    circular paraboloid
cg                       A circular paraboloid is an axially symmetric quadric
cg                         surface for which the standard equation is:
cg                               -QZ*z + x^2 + y^2 = 0.
cg                         This is the shape of a telescope reflector or the
cg                         reflector behind a beamed light source.
cg
cg                         To find the distance from a point to a circular
cg                         paraboloid, use command "distance", "proximal" or
cg                         "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and a circular paraboloid, use command "distance".

cg    circum             Abbreviation for circumference.

cg    circumference      To find the circumference of a circle or a circular
cg                         cylinder, use command "circle", "cylinder", "disk"
cg                         or "intcirc".

cg    circumscribed      See "circumscribed circle", "circumscribed sphere".

cg    circumscribed circle
cg                       When a triangle is created or displayed, the center
cg                         and radius of the circumscribed circle is displayed.
cg                         The center is at the intersection of the
cg                         perpendicular bisectors of the edges.
cg                         See "inscribed circle", "centroid", "orthocenter",
cg                         commands "circle", "kiss", "trig".
cg                         Any circumscribed circle tangent externally to each
cg                         of three mutually tangent circles may be found with
cg                         command "kiss".


cg    circumscribed sphere
cg                       A sphere may be circumscribed outside a regular
cg                         polyhedron, such as a tetrahedron, a cube, an
cg                         octahedron, a dodecahedron or an icosahedron,
cg                         so that it passes through every face of the regular
cg                         polyhedron.  See "inscribed sphere".
cg                         Any circumscribed sphere, tangent internally to each
cg                         of four mutually tangent spheres may be found with
cg                         command "kiss".

cc    cl                 A synonym for cluster.

cc    CLNAME             The name of a cluster of points.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.
cc                         No cluster name may be "+", "-", "all", "h", "help",
cc                         "list", "point" or "thru", begin with "." or "!" or
cc                         contain ";".
cc                         Specified with command "cluster".
cc                         Also referred to as CLNAME1, CLNAME2, CLNAME3, ...
cc
cc                         Clusters may appear in commands:
cc                         accelerate, area, cluster, copy, delete, distance,
cc                         invert, mesh, move, project, reflect, rename, rotate,
cc                         scale, twist, where.
cc                         Also see commands:  last, list, repack, search, sort.

cc    closest            See "minimum", "nearest", "proximal".

cg    cluster            A cluster is a named set of points.  Points may be
cg                         added or removed by name or by the names of clusters
cg                         containing the points, added by mesh status, or by
cg                         presence in a tetrahedron, brick or zone.
cg                         Any duplicate point names in a cluster will be
cg                         deleted.  Any point may be in any number of clusters.
cg                         The maximum number of clusters is now 100.
cg                         The maximum number of points assigned to clusters is
cg                         now 1000, counting points assigned to more than one
cg                         cluster.
cg                         Clusters may be copied, deleted, renamed, and listed.
cg                         Clusters may be translated, rotated, reflected,
cg                         inverted, scaled and projected.
cg                         The points in a cluster may be deleted.
cg
cg                         No cluster name may be "+", "-", "all", "comp.", "h",
cg                         "help", "list", "point" or "thru", begin with "!" or
cg                         contain ";".
cg
cg                         Clusters may be sorted by name with command "sort".
cg
cg                         The following commands relate to clusters:
cg                         accelerate, area, cluster, copy, debug, delete,
cg                         distance, help, invert, last, list, mesh, move,
cg                         point, project, reflect, rename, repack, rotate,
cg                         scale, search, sort, symbol, synonym, tables, twist,
cg                         where.

cc    cluster            An option in command "debug", to display GEOM internal
cc                         parameters and variables for clusters of points:
cc                         nclustm, nclusts, aclust, laclust, aclusts, laclusts,
cc                         npairm, npairs, apaircl, apairpt.
cc                         Synonyms:  [cluster, cl].

cc    cluster            Command to display or create clusters of existing
cc                         points, or to modify an existing cluster by adding or
cc                         removing points.  Creating a cluster replaces any
cc                         existing cluster having the same name.  The display
cc                         will include the coordinates of each point, and the
cc                         minimum, maximum, average and standard deviation of
cc                         each of the coordinates.
cc                         See "do loop use".
cc
cc                         Command "cluster" relates to objects:  brick,
cc                         cluster, mesh, point, symbol, tetrahedron, zone.
cc
cc                         Forms include:
cc
ccin                       help cluster
ccin                       cluster [help]
cc
cc                           Display the command options.
cc
ccin                       cluster [all,list]
cc
cc                           Display all clusters.
cc
ccin                       cluster list CLNAME1 CLNAME2 CLNAME3 ...
cc
cc                           Display clusters CLNAME1, CLNAME@, CLNAME3, ...,
cc                           with or without subscripts.
cc
ccin                       cluster CLNAME
cc
cc                           Display cluster CLNAME.
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         CLNAME to form the name by incrementing or
cc                         decrementing the base name for clusters.
cc                         See command "last", "increment names".
cc
ccin                       cluster CLNAME all
cc
cc                           Create new cluster CLNAME, consisting of all
cc                           points.
cc
ccin                       cluster CLNAME = PNAME1 ... PNAME2 [thru] PNAME3 ...
cc
cc                           Create new cluster CLNAME, consisting of points
cc                           PNAME1, ..., PNAME2 [, through] PNAME3, ...
cc                           If option "thru" is used, the adjacent points need
cc                           not exist.  Any error cancels entire command.
cc
ccin                       cluster CLNAME & PNAME1 ... PNAME2 [thru] PNAME3 ...
cc
cc                           Add to existing cluster CLNAME (do not use "+" or
cc                           "-"), points PNAME1, ..., PNAME2 [, through]
cc                           PNAME3, ...
cc                           If option "thru" is used, the adjacent points need
cc                           not exist.  A warning message is displayed if the
cc                           cluster CLNAME does not already exist.  Any error
cc                           cancels entire command.
cc
cc                           This command could be placed between commands "do"
cc                           and "enddo", to create a do loop over subscripted
cc                           point names, to add them to a cluster.
cc
ccin                       cluster CLNAME - PNAME1 ... PNAME2 [thru] PNAME3 ...
cc
cc                           Remove from existing cluster CLNAME (do not use
cc                           "+" or "-"), points PNAME1, ..., PNAME2 [, through]
cc                           PNAME3, ...  If option "thru" is used, the adjacent
cc                           points need not exist.  WARNING:  an error in one
cc                           word does not cancel the entire command.  For a
cc                           backup, copy the cluster before modifying.
cc
cc                           This command could be placed between commands "do"
cc                           and "enddo", to create a do loop over subscripted
cc                           point names, to remove them from a cluster.
cc
ccin                       cl CLNAME cl CLNAME1 ... CLNAME2 [thru] CLNAME3 ...
cc
cc                           Create new cluster CLNAME, consisting of existing
cc                           clusters CLNAME1, ..., CLNAME2 [, through] CLNAME3,
cc                           ...  If option "thru" is used, the adjacent
cc                           clusters need not exist.  Add to existing cluster
cc                           CLNAME if CLNAME is in the list of cluster names.
cc                           Any error cancels entire command.
cc                           Note:  "cl" is a synonym for "cluster".
cc
ccin                       cl CLNAME cl CLNAME ... CLNAME2 [thru] CLNAME3 ...
cc
cc                           Add to existing cluster CLNAME, (do not use "+" or
cc                           "-") the existing clusters CLNAME1, ..., CLNAME2 [,
cc                           through] CLNAME3, ...  If option "thru" is used,
cc                           the adjacent clusters need not exist.  Any error
cc                           cancels entire command.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                           This command could be placed between commands "do"
cc                           and "enddo", to create a do loop over subscripted
cc                           cluster names, to add them to a cluster.
cc
ccin                       cl CLNAME cl - CLNAME1 ... CLNAME2 [thru] CLNAME3 ...
cc
cc                           Remove from existing cluster CLNAME (do not use
cc                           "+" or "-"), all points in existing clusters
cc                           CLNAME1, ..., CLNAME2 [, through] CLNAME3, ...
cc                           If option "thru" is used, the adjacent points need
cc                           not exist.  A warning message is displayed if the
cc                           cluster CLNAME does not already exist.
cc                           WARNING:  an error in one word does not cancel the
cc                           entire command.  For a backup, copy the cluster
cc                           before modifying.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                           This command could be placed between commands "do"
cc                           and "enddo", to create a do loop over subscripted
cc                           cluster names, to remove them from a cluster.
cc
cc                         cluster CLNAME cluster comp. CLNAME1
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           not in cluster CLNAME1.  This is the Boolean
cc                           "complement" of the cluster CLNAME1.
cc
cc                         cluster CLNAME cl CLNAME1 .and. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are in both clusters CLNAME1 and CLNAME2.
cc                           This is the Boolean "and" or "intersection" of
cc                           clusters CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .nand. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are not in both clusters CLNAME1 and CLNAME2.
cc                           This is the Boolean "complement" of the "and" or
cc                           "intersection" of clusters CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .nor. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are not in cluster CLNAME1 and not in cluster
cc                           CLNAME2.  This is the Boolean "complement" of the
cc                           "intersection" of clusters CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .not. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are in cluster CLNAME1 but not in cluster
cc                           CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .or. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are in cluster CLNAME1 or in cluster CLNAME2.
cc                           This is the Boolean "or" or "union" of clusters
cc                           CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .xnor. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are either in both clusters or in neither
cc                           cluster CLNAME1 and CLNAME2.  This is the Boolean
cc                           "complement" of the "exclusive or" of clusters
cc                           CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
cc                         cluster CLNAME cl CLNAME1 .xor. CLNAME2
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           that are in cluster CLNAME1 but not in cluster
cc                           CLNAME2, or in cluster CLNAME2 but not in cluster
cc                           CLNAME1.  This is the Boolean "exclusive or" of
cc                           clusters CLNAME1 and CLNAME2.
cc                           Note:  "cl" is a synonym for "cluster".
cc
ccin                       cluster CLNAME brick BRNAME
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           inside of brick BRNAME.
cc
ccin                       cluster CLNAME tetrahedron TETNAME
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           inside of tetrahedron TETNAME.
cc
ccin                       cluster CLNAME zone ZNAME
cc
cc                           Create new cluster CLNAME, consisting of all points
cc                           inside of zone ZNAME.
cc
ccin                       cluster CLNAME mesh [all]
cc
cc                           Create new cluster CLNAME, consisting of all mesh
cc                           points.
cc
ccin                       cluster CLNAME nomesh
cc
cc                           Create new cluster CLNAME, consisting of all
cc                           non-mesh points.
cc
ccin                       cluster CLNAME mesh block
cc
cc                           Create new cluster CLNAME, consisting of all mesh
cc                           points in the mesh block.
cc
ccin                       cluster CLNAME mesh vacuum
cc
cc                           Create new cluster CLNAME, consisting of all mesh
cc                           points with x, y, z coordinates of -10^99 or less.
cc
cc                         Synonyms:  [.and., .int.], [.or., .un.],
cc                         [.xnor., .eqv.], [block, bl],
cc                         [brick, br], [cluster, cl], [help, h],
cc                         [tetrahedron, tet, tetra], [zone, z, zn].

cc    cluster            An option in commands "accelerate", "area", "cluster",
cc                         "copy", "delete", "distance", "invert", "last",
cc                         "list", "mesh", "move", "project", "reflect",
cc                         "rename", "repack", "rotate", "scale", "sort",
cc                         "twist" and "where", to perform the specified
cc                         operation on one or more clusters of points.
cc                         Synonyms:  [cluster, cl].

cg    cluster arrays     Clusters may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cc    cmd                A synonym for command in command "input".

cn    cmd                Indicates a command summary file.
cn                         The command summary file from GEOM is geom_cmd.

cg    cn                 In columns 1-2 of geom_base, indicates a file name.

cc    CNNAME             The name of a circular cone.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.  May not be the same as any other quadric
cc                         surface name QNAME.  Also referred to as CNNAME1,
cc                         CNNAME2, ..., CONE(1), CONE(2).  Specified with
cc                         commands "cone", "quadric" or "axisym".
cc                         No cone name may be "+", "-", "all", "h", "help",
cc                         "list", "point" or "thru", begin with "!" or contain
cc                         ";".
cc
cc                         Cones may appear in commands:
cc                         accelerate, arc, axisym, cone, copy, delete,
cc                         distance, extrema, help, invert, last, list, move,
cc                         operator, point, project, proximal, quadric, reflect,
cc                         rename, repack, rotate, scale, search, side, slice,
cc                         sort, track, triple, vector.

cg    code               The code name is GEOM.

cg    coefficient        To find the real coefficients of a polynomial equation
cg                         with from two to four specified real and/or complex
cg                         roots, use command "roots", option "=".
cg
cg                         To find the real coefficients of an Nth-order
cg                         polynomial equation with N specified real roots,
cg                         use command "root", option "=".
cg
cg                         To find the real and/or complex roots of a linear,
cg                         quadratic, cubic or quartic polynomial equation with
cg                         real coefficients, use command "roots".
cg
cg                         To search for real roots, extrema and inflection
cg                         points of a polynomial equation by Newtonian
cg                         iteration, use command "root".

cg    cofactor           If an integer N has an integer factor M, the cofactor
cg                         of M is N / M.
cg

cg    coil               A coil is a curve at a fixed distance from an axis,
cg                         with its angular coordinate around the axis a
cg                         linear function of its displacement parallel to the
cg                         axis.  To generate a family of points arrayed along a
cg                         coil, use command "point ... move" to create a family
cg                         of points along a straight line parallel to the coil
cg                         axis, then use command "cluster" to create a cluster
cg                         consisting of the points, and then operate on the
cg                         cluster with command "twist", option "axial".

cg    coincident         Two geometric objects are coincident if they have the
cg                         same size, shape, position and orientation, or the
cg                         difference between them is no more than the
cg                         estimated error in calculating that difference, based
cg                         on the tolerance limit TOL.
cg
cg                         To test points, lines, triangle, planes, spheres or
cg                         circular cylinders for coincidence, use command
cg                         "distance".
cg
cg                         To test two spheres for coincidence of their centers
cg                         or their surfaces, or to test two circular cylinders
cg                         for coincidence of their axes or their surfaces,
cg                         use command "distance".

cg    coincident         See "coincident planes".

cg    coincident planes
cg                       A pair of coincident planes may be represented by a
cg                         single quadric surface for which the standard
cg                         equation is x^2 = 0.
cg                         This factors into the two equations:
cg                           x = 0 (a simple plane),
cg                           x = 0 (a simple plane, coincident with the first).
cg
cg                         The general implicit quadric equation for coincident
cg                         planes is the square of the implicit quadric equation
cg                         for a simple plane:
cg                           (QC + QX * x + QY * y + QZ * z)^2 = 0.
cg
cg                         This is a limiting case of parallel planes or
cg                         intersecting planes.
cg                         See "non-simple planes".
cg
cg                         To create such a quadric surface, use command
cg                         "quadric", option "plane".

cc    col                An option in command "sudoku", to assign up to 9
cc                         digits to a Sudoku column.

cg    collision          See "mean free path".

cg    colon              The colon character, ":".

cg    column             In an input line, the character position counting from
cg                         the first (leftmost) character, including blank
cg                         characters.  Control characters displayed as two
cg                         characters count as only one column.  Tab characters
cg                         may be any number of columns.

cg    column             See "family of objects", "move", "scale".

cc    comb               An option in command "big", to find the number of
cc                         combinations of M things taken N at a time.
cc
cc                         big BIGNAME =  M comb N


cc    comb               An option in command "icalc", to find the number of
cc                         combinations of M things taken N at a time.
cc
cc                         icalc M comb N

cg    combinations       The number of combinations of M things taken N at a
cg                         time is C(M,N) = M! / (N! * (M - N)!).
cg                         Use command "icalc M comb N" or
cg                         "big BIGNAME = INT1 comb INT2".
cg                      .  See "permutations".

cc    comm               A synonym for commands.

cc    comma              The comma character, ",".

cc    COMMAND            In command "help COMMAND" or "COMMAND help", any
cc                         command name or the word "all".
cc                         See "commands", "help".

cc    COMMAND            In any command, the command key word.  See "commands".
cc
cc                         Forms include:
cc
ccin                       COMMAND
cc
cc                           For most commands, display forms and options.
cc                           Exceptions include commands "angles", "coordinate",
cc                           "input", "output", "time", "title", and "when",
cc                           which display other information, and
cc                           commands "delimiter", "endif", "indo", "redo",
cc                           "return" and "undo" which perform some operation.
cc
ccin                       help COMMAND
ccin                       COMMAND help
cc
cc                           For all commands, display forms and options.
cc
ccin                       COMMAND ...
cc
cc                           See the description for each command in geom_base.
cc
ccin                       COMMAND ... ! COMMENT
cc
cc                           Command COMMAND with appended comment COMMENT.
cc
ccin                       COMMAND1 ...;COMMAND2 ... ; COMMAND3 ...
cc
cc                           Multiple commands COMMAND1, COMAND2 and COMMAND3 on
cc                           the same line. The ";" needs no delimiter.
cc
ccin                       COMMAND1 ... ! COMMENT1 ; COMMAND2 ... ! COMMENT2
cc
cc                           Multiple commands COMMAND1 and COMMAND2, with
cc                           appended comments COMMENT1 and COMMENT2,
cc                           respectively.
cc
cc                         Synonyms:  [help, h].

cc    command            An option in command "input", used in place of a
cc                         file name, to indicate that one or more lines from
cc                         the input lines saved in memory are to be
cc                         executed or displayed.

cg    command            See "command form", "command list", "command summary".

cg    command form       Commands begin with a command word or one of its
cg                         synonyms, and may have additional arguments, and
cg                         must always be ended by typing the <return> key, or
cg                         with certain exceptions, by the command separator
cg                         character ";" if followed by another command on the
cg                         same input line, or by the comment separator
cg                         character "!" if followed by a comment on the same
cg                         input line.
cg                         The default field delimiter is a blank character,
cg                         but may be changed with command "delimiter".
cg                         Arguments are separated by the field delimiter.
cg                         Any argument beginning with "!" is the beginning of
cg                         an appended comment.
cg                         The <return> key must be typed at the end of every
cg                         input line typed at the user's terminal.
cg
cg                         Command arguments are displayed in lower case for
cg                         arguments to be typed literally as shown, and in
cg                         UPPER CASE for arguments for which the user
cg                         must provide an ASCII name (using any case), an
cg                         integer or floating point value, an integer or
cg                         floating point variable or a symbol.
cg
cg                         Any argument which allows a floating point value may
cg                         be replaced by the name of an integer or floating
cg                         point variable.
cg
cg                         Except for the argument LINE in command "indo" or
cg                         "redo", any argument which only allows an integer
cg                         value may be replaced by an integer variable.
cg
cg                         With certain exceptions (see "symbol"), any argument,
cg                         may be replaced by a symbolic word which, after
cg                         symbol replacement, is an acceptable value for that
cg                         argument.
cg
cg                         The first word of a command, and additional words if
cg                         desired, may be replaced by a previously defined
cg                         alias (see command "alias").
cg
cg                         See "commands", "key words", "arguments", "help".

cg    command list       See "input", "macro".
cg                         A list of commands from the current session is saved
cg                         in file geom_cmd, and may be displayed or executed
cg                         again with command "input geom_hsp [options]".
cg                         Another such list is saved internally, and may be
cg                         displayed or executed again with command
cg                         "input command [options]".

cg    command summary    See "geom_cmd", command "input command".

cg    command use        See the entries in this file for each object type.

cc    commands           Command to display an alphabetic list of command words,
cc                         including synonyms.
cc
cc                         Forms include:
cc
ccin                       help commands
ccin                       commands [help]
cc
cc                           Display an alphabetic list of command words,
cc                           including synonyms.
cc
cc                         Synonyms:  [commands, alph, comm], [help, h].

cc    commands           The currently implemented commands are listed below,
cc                         with their synonyms.  See the entry for each command,
cc                         for a description of required and optional arguments.
cc                         Also see "key words", "help", "command form",
cc                         "arguments".  Also see files geom_commands and
cc                         geom_input.
cc                         Use command "alias" to create your own command names,
cc                         with or without additional arguments.
cc                         Use command "alph" to display an alphabetic list of
cc                         all commands and their synonyms.
cc                         Use command "synonym" to find any synonym for a
cc                         given command or any command with a given synonym.
cc
cc                         .
cc                         accelerate    accel
cc                         alias         al      a
cc                         alph          commands              comm
cc                         angles        angle   ang
cc                         arc
cc                         area
cc                         axisym
cc                         base
cc                         big
cc                         bin
cc                         bisect
cc                         brick         br
cc                         circle        circ
cc                         cluster       cl
cc                         commands      comm     alph
cc                         cone
cc                         contfr        cf
cc                         coordinate    coord    cs           system    sys
cc                         copy          cp       duplicate    dup
cc                         cross         outer
cc                         crt
cc                         cut           slice
cc                         cute
cc                         cuts
cc                         cylinder      cyl
cc                         define        def
cc                         debug
cc                         delete        del      remove       rm
cc                         delimiter     delimit  delim
cc                         disk          dk
cc                         distance      dist     intersect    inter     int
cc                         do
cc                         dot           inner
cc                         duplicate     dup      copy         cp
cc                         ellipsoid     ellipse  ell          el
cc                         end           exit     split        quit
cc                         enddo
cc                         endif
cc                         environment   env      setup
cc                         error         err
cc                         exit          end      quit         split
cc                         extrema       extr
cc                         factor        totient
cc                         goto
cc                         help          h
cc                         hex
cc                         hyperb        saddle
cc                         icalc
cc                         id            title
cc                         if
cc                         increment     incr
cc                         indo
cc                         inner         dot
cc                         input         in       i            read      rd  r
cc                         input         call
cc                         intcirc
cc                         intersect     inter    int          distance  dist
cc                         invert        inv
cc                         iris
cc                         kiss
cc                         last
cc                         line          ln       l
cc                         list          print
cc                         lock          zzz
cc                         marker        mark     m
cc                         math
cc                         mcvol
cc                         mesh
cc                         misc
cc                         move          mv       translate    trans
cc                         object        obj
cc                         operator      oper     op
cc                         outer         cross
cc                         output        out      o            write     wr  w
cc                         page
cc                         parse
cc                         pdf
cc                         plane         pl
cc                         plot
cc                         point         pnt      pt           p
cc                         polygon       polyg    pg
cc                         polyhedron    polyh    ph
cc                         project       proj
cc                         prompt
cc                         proximal      prox
cc                         quadric       quad     q
cc                         quit          end      exit         split
cc                         random        ?
cc                         ratio         rat
cc                         read          rd       r            input     in  i
cc                         redo
cc                         reflect       refl
cc                         remove        rm       delete       del
cc                         rename        switch   sw
cc                         repack
cc                         return        rtn
cc                         root
cc                         rootf
cc                         roots
cc                         rotate        rot
cc                         saddle        hyperb
cc                         sample
cc                         search        find
cc                         scale
cc                         set           s        variable     var
cc                         setup         environment           env
cc                         side
cc                         sizes         tables
cc                         slice         cut
cc                         solve
cc                         sort
cc                         sphere        sph
cc                         spin
cc                         split         end      exit         quit
cc                         status        stat
cc                         steiner       stein
cc                         sudoku        su
cc                         switch        sw       rename
cc                         symbol        symb     sym
cc                         synonym       syn
cc                         system        sys      coordinate   coord     cs
cc                         tables        sizes
cc                         tetrahedron   tetra    tet
cc                         time          t
cc                         title         id
cc                         tol
cc                         trace
cc                         track         trk
cc                         translate     trans    move         mv
cc                         triangle      tri
cc                         trig
cc                         triple
cc                         twist         tw
cc                         undo          u
cc                         variable      var      set          s
cc                         vector        vect     v
cc                         vi
cc                         volume        vol
cc                         walk
cc                         when
cc                         where
cc                         write         wr       w            output    out o
cc                         zone          zn       z

cc    comment            A comment line is any input line with one of the
cc                         following forms, where COMMENT is any desired
cc                         comment, which may include leading blanks:
cc
ccin                       !COMMENT      (starting in column 1)
ccin                       #COMMENT      (starting in column 1)
ccin                       *COMMENT      (starting in column 1)
ccin                       /COMMENT      (starting in column 1)
ccin                       C COMMENT     (starting in any column)
ccin                       c COMMENT     (starting in any column)
ccin                       C++++ COMMENT (starting in any column)
ccin                       c++++ COMMENT (starting in any column)
ccin                       C---- COMMENT (starting in any column)
ccin                       c---- COMMENT (starting in any column)
ccin                       C.... COMMENT (starting in any column)
ccin                       c.... COMMENT (starting in any column)
ccin                       CCCOMMENT     (starting in column 1)
ccin                       ccCOMMENT     (starting in column 1)
cc
cc                         Comment lines are echoed in the output file.
cc
cc                         An appended comment is any character "!" following
cc                         a command and a field delimiter, and the rest of the
cc                         input line after the "!":
cc
cc                           COMMAND !COMMENT
cc
cc                         You may create your own comment corresponding to any
cc                         single character you desire, with command "marker".
cc                         See "definition", "alias".
cc
cc                         You may create your own comment corresponding to any
cc                         object name or other word you desire, with
cc                         command "alias".  See "definition", "marker".

cg    Comments           See "comment".

cg    Common             See "Common factors".

cg    common             See "common divisor", "common multiplier".

cg    common divisor     A common divisor divides two or more numbers without
cg                         remainder.  A greatest common divisor (gcd) is the
cg                         largest such number, and must contain only those
cg                         prime factors common to all of the numbers, with
cg                         each such prime factor to the least power of that
cg                         factor in any of the numbers.
cg                         If the gcd of a set of numbers is 1, the numbers are
cg                         all relatively prime.
cg                         See command "icalc", option "gcm".

cg    Common factors     In the display for command "factor", the number of
cg                         integers in the set (1, ..., N - 1), where N is the
cg                         integer being factored, that have common factors
cg                         with N.
cg                         The value "Totient function" is the number of
cg                         integers in the set (1, ..., N - 1) that are
cg                         relatively prime to N (have no common factor other
cg                         than 1).

cg    common multiplier
cg                       A common multiplier is divisible by two or more numbers
cg                         without remainder.  A least common multiplier (lcm)
cg                         is the smallest such number, and must contain all of
cg                         the prime factors found any any of the numbers, with
cg                         each such prime factor to the greatest power of that
cg                         factor in any of the numbers.
cg                         See commands "icalc" and "variable", option "lcm".

cc    comp.              An option in command 'icalc", to multiply an integer
cc                         by the Boolean complement of another integer.
cc                         M comp. N means M times the complement of N.
cc                         comp. N:  replace 0 with 1 and 1 with 0.
cc                         See "Boolean".

cc    comp.              An option in command "cluster", to create a cluster
cc                         consisting of all of the points not in a specified
cc                         cluster.  This is the Boolean "complement" of the
cc                         specified cluster.

cg    complement         See "Boolean".

cg    complex            Complex numbers are not allowed as input, except in
cg                         command "roots", options "=" and "?".
cg                         Complex roots displayed by command "roots" are the
cg                         only complex numbers displayed in the output data.
cg
cg                         A complex variable may be written in various forms:
cg                         z = x + i*y = r*exp(i*a) = r*cos(a) + i*r*sin(a),
cg                         where r = sqrt(x^2 + y^2), a = arctan (y / x),
cg                         x = r*cos(a), y = r*sin(a).
cg                         Complex roots of polynomial equations with real
cg                         coefficients only occur in the conjugate pairs
cg                         z = x + i * y and z' = x - i * y.
cg                         Alternate forms for z' are:
cg                         z' = x - i*y = r*exp(-i*a) = r*cos(a) - i*r*sin(a).
cg                         Also, z * z' = r^2, z + z' = 2*x, z - z' = 2*y*i.

cg    component          A vector has a component in each of the 3 coordinate
cg                         directions.  See "coordinate system", "vector".
cg                         See "coordinate conversion", "vector conversion".
cg
cg                         A tensor operator has nine components, in a 3 by 3
cg                         matrix.  See "operator".

cg    composite          See "composite number".

cg    composite number   A composite number is a positive non-prime integer.
cg                         Every known positive composite (non-prime) integer
cg                         N can be expressed as the product of a unique
cg                         collection of positive primes.  These are the prime
cg                         factors of N.  If N has the prime factors P1, P2,
cg                         ..., PN, then N = P1^a1 * P2^a2 * ... * PN^aN, where
cg                         a1, a2, ..., aN are positive integer exponents.

cg    compress           Output files may be compressed by editing them.
cg                         Some examples, using UNIX text editor VI, follow:
cg
cg                         :%s/  *$//
cg
cg                           Remove all trailing blanks.
cg
cg                         :%s/  */ /g
cg
cg                           Reduce all multiple blanks to single.
cg
cg                         :%s/00*E/E/g
cg
cg                           Remove all trailing zeros on floating point output.
cg
cg                         :%s/E+00/g
cg
cg                           Remove all zero exponents on floating point output.
cg
cg                         :%s/.......E/E/y
cg
cg                           Remove the final seven (for example) significant
cg                           figures after the decimal point of floating point
cg                           output.
cg
cg                         :g/^$/d
cg
cg                           Remove blank lines.

cc    conc               A synonym for concentric.

cc    concatenation      A new integer may be created by concatenating two
cc                         integers, e.g., 111 and 33333 may be concatenated to
cc                         form 11133333.  See command "big".
cc                         This is a convenient way to add digits at the
cc                         beginning or end of a big integer.

cc    concentric         An option in command "cylinder", to create a family of
cc                         concentric circular cylinders with a specified axis
cc                         point, axis direction, and equally spaced between two
cc                         radii.
cc                         See "move", "nest", "parallel", "rotate", "scale".
cc
cc                         This command option can be replaced, using a do loop.
cc                         See "do loop use", commands "do", "enddo".

cc    concentric         An option in command "sphere", to create a family of
cc                         concentric spheres with a specified center point,
cc                         inner radius, outer radius, and equally spaced
cc                         between two radii.
cc                         See "move", "nest", "parallel", "rotate", "scale".
cc
cc                         This command option can be replaced, using a do loop.
cc                         See "do loop use", commands "do", "enddo".

cg    concentric         Two spheres are concentric if they share the same
cg                         center.  Two circular cylinders are concentric if
cg                         they share the same axis.  To see if two spheres are
cg                         concentric, use command "distance".  To see if two
cg                         circular cylinders are concentric, use command
cg                         "distance".

cg    conditional        The execution of a block of input lines may be made
cg                         conditional by preceding the block with command
cg                         "if ...", and following the block with command
cg                         "endif ...".  Command "if ..." specifies the
cg                         condition for executing the block of input lines.

cg    cone               A cone is a surface in 3-D space described by an
cg                         implicit quadric equation, and is a limit case of a
cg                         hyperboloid of one or two sheets.  A conical surface
cg                         includes both sheets, on opposite sides of the vertex
cg                         point.  At any point in the surface, a straight line
cg                         drawn through that point and through the vertex point
cg                         lies entirely within the surface.  Along with planes,
cg                         cylinders, hyperbolic paraboloids and hyperboloids
cg                         of one sheet, a cone is a ruled surface.
cg
cg                         The standard forms of the implicit equations for
cg                         conical quadric surfaces are as follows (each
cg                         coefficient must have the preceding sign):
cg
cg                         Real elliptic cone:
cg                                              x^2 + QYY*y^2 - |QZZ|*z^2 = 0
cg                         Real circular cone:
cg                                                  x^2 + y^2 - |QZZ|*z^2 = 0
cg                                         or       x^2 + y^2 = K^2 * z^2
cg                         Imaginary elliptic cone:
cg                                                x^2 + QYY*y^2 + QZZ*z^2 = 0
cg                         Imaginary circular cone:
cg                                                    x^2 + y^2 + QZZ*z^2 = 0
cg                                         or         x^2 + y^2 = -K^2 * z^2
cg                         where K = tan (ALPHA), and ALPHA is the half-angle
cg                         at the vertex.  K = sqrt (QZZ/QXX).
cg
cg                         Given a cone on the z axis, through the points
cg                         (R1, Z1), (R2, Z2), where R1^2 = X1^2 + Y1^2, and
cg                         R2^2 = X2^2 + Y2^2, the equation of the cone is
cg                         (Z2-Z1)^2*(x^2+y^2) - (R2-R1)^2*(z-ZVER)^2 = 0,
cg                         where ZVER = (Z1 * R2 - Z2 * R1) / (R2 - R1).
cg
cg                         See "half-angle".  Also see "phi cone".
cg
cg                         The word "cone" in a command means a real circular
cg                         cone.  Otherwise, use "quadric".
cg
cg                         To find the distance from a point to a cone, use
cg                         command "distance", "proximal" or "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and a cone, use command "distance".
cg
cg                         The following commands relate to circular
cg                         cones:
cg                         accelerate, arc, axisym, cone, copy, debug, delete,
cg                         distance, extrema, help, invert, last, list, move,
cg                         operator, point, proximal, quadric, reflect, rename,
cg                         repack, rotate, scale, search, side, slice, sort,
cg                         symbol, synonym, tables, track, triple, vector, zone.
cg
cg                         A family of nested cones, with the same vertex and
cg                         axis, but with equally spaced vertex half-angles,
cg                         may be created with command "cone", option "nest".
cg                         See "parallel planes", "rotated planes",
cg                         "concentric".
cg
cg                         Also see "phi cone".

cc    cone               In a command, means a circular cone, except in
cc                         command "cone", option "scale", when the scaling
cc                         operator is linear or radial with an axis not
cc                         parallel to that of the base cone, elliptic cones
cc                         are created.

cc    cone               Command to display or create circular cones (except
cc                         that linear or radial scaling may create elliptic
cc                         cones).  Creating a cone replaces any existing
cc                         quadric surface having the same name.
cc                         The normal vectors will be pointed radially outward.
cc                         See "quadric" for other options.
cc                         See "do loop use".
cc
cc                         Command "cone" relates to objects:  axisym, cone,
cc                         line, operator, point, quadric, symbol, variable
vv                         vector.
cc
cc                         Forms include:
cc
ccin                       help cone
ccin                       cone [help]
cc
cc                           Display the command options.
cc
ccin                       cone [all,list]
cc
cc                           Display all circular cones (short display).
cc
ccin                       cone list CNNAME1 CNNAME2 CNNAME3 ...
cc
cc                           Display circular cones CNNAME1, CNNAME2, CNNAME3,
cc                           ..., with or without subscripts (short display).
cc
ccin                       cone CNNAME
cc
cc                           Display circular cone CNNAME (long display).
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         CNNAME or CONE(2) to form the name by incrementing or
cc                         decrementing the base name for circular cones.
cc                         See command "last", "increment names".
cc
ccin                       cone CNNAME line PAXIS VAXIS ALNAME
cc
cc                           Create circular cone CNNAME on the axis specified
cc                           by point PAXIS and vector VAXIS, and passing
cc                           through the end points of line ALNAME.  This is the
cc                           best way to specify the bounding surfaces of an
cc                           axially symmetric zone whose projected area is a
cc                           polygon.
cc
ccin                       cone CNNAME fit PVER VAXIS PNAME2
cc
cc                           Create circular cone CNNAME with vertex point PVER,
cc                           axis vector VAXIS, and passing through the point
cc                           PNAME2.
cc
ccin                       cone CNNAME angle PVER VAXIS ANGLE
cc
cc                           Create circular cone CNNAME with vertex point PVER,
cc                           axis vector VAXIS, and vertex half-angle ANGLE.
cc
ccin                       cone CNNAME nest NUMCONE INC PVER VAXIS ANG1 ANG2
cc
cc                           Create a family of NUMCONE nested circular cones
cc                           CNNAME, ..., with names incremented by INC
cc                           characters, with the same vertex point PVER and
cc                           axis vector VAXIS, and with vertex half-angles
cc                           equally spaced from ANG1 to ANG2.
cc                           See "increment names".
cc
cc                           This command can be replaced, by using commands
cc                           "do" and "enddo" to create a do loop over any of
cc                           the "cone" commands, using cones with subscripted
cc                           names, with more general specification of
cc                           properties.
cc
ccin                       cone CONE(2) move NUMCONE INC CONE(1) VMOVE
cc
cc                           Create a family of NUMCONE circular cones CONE(2),
cc                           ..., with names incremented by INC characters, and
cc                           spaced at intervals of vector VMOVE, starting from
cc                           circular cone CONE(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       cone CONE(2) rotate NUMCONE INC CONE(1) OPNAME PINV
cc
cc                           Create a family of NUMCONE circular cones CONE(2),
cc                           ..., with names incremented by INC characters, by
cc                           rotating the preceding circular cone with operator
cc                           OPNAME and invariant point PINV, starting from
cc                           circular cone CONE(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       cone CONE(2) scale NUMCONE INC CONE(1) OPNAME PINV
cc
cc                           Create a family of NUMCONE cones CONE(2), ..., with
cc                           names incremented by INC characters, by scaling the
cc                           preceding cone with operator OPNAME and invariant
cc                           point PINV, starting from circular cone CONE(1).
cc                           See "increment names".  WARNING:  a linear or
cc                           radial scaling axis not parallel to that of CONE(1)
cc                           will produce elliptic cones.
cc                           See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
cc                         Synonyms:  [help, h], [line, l, ln],
cc                         [move, mv, trans, translate], [point, p, pnt, pt],
cc                         [rotate, rot].

cc    cone               An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on one or more circular cones.

cg    cone               See "cone, circular", "cone, elliptic".

cg    cone arrays        Cones may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cc    CONE(1)            In command "cone", the name of a base cone, used to
cc                         create a family of cones.

cg    cone, circular     For the circular cone:
cg                         QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QXX = QYY > 0, QZZ < 0),
cg                         the center and vertex are at x = y = z = 0,
cg                         the main axis is the z axis, and
cg                         the half-angle from the z axis is
cg                         atan (sqrt (-QZZ/QXX)).

cg    cone, elliptic     For the elliptic cone:
cg                         QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QXX => QYY > 0, QZZ < 0),
cg                         the center and vertex are at x = y = z = 0,
cg                         the main axis is the z axis,
cg                         the eccentricity is sqrt (1 - QYY / QXX) < 1,
cg                         the half-angle from the z axis toward the x axis is
cg                         atan (sqrt (-QZZ/QXX)), and
cg                         the half-angle from the z axis toward the y axis is
cg                         atan (sqrt (-QZZ/QYY).

cg    cones              A family of circular cones may be created with
cg                         command "cone", options "concentric", "move",
cg                         "rotate" or "scale" (with restrictions) or as
cg                         follows:
cg
cg                         p pinv ...
cg
cg                           Create an invariant point, if needed.
cg
cg                         cone CONE(1) (options)
cg
cg                           Create a base cone.
cg
cg                         op opr (options)
cg
cg                           Create a tensor operator, to reflect, rotate,
cg                           invert or scale, if needed.
cg
cg                         v vmove (options)
cg
cg                           Create a vector for use as a translation operator,
cg                           if needed.
cg
cg                         cp CONE(1) CONE(2)
cg
cg                           Copy cone CONE(1) to the first cone.
cg
cg                         Repeat the following block of commands as many times
cg                         as needed to create the rest of the family of cones.
cg                         See "shortcuts", "saved input lines".
cg
cg                         move cone CONE(1) vmove
cg
cg                           Move the base cone by amount vmove, if needed.
cg
cg                         [invert,reflect,rotate,scale] cone CONE(1) opr [pinv]
cg
cg                           Invert, reflect, rotate or scale the base cone with
cg                           tensor operator opr, if needed.
cg
cg                         copy cone CONE(1) +
cg
cg                           Copy the base cone to the next cone.

cg    conflicts          Tests are made for conflicts between the names of
cg                         preset synonyms, symbols and aliases created by
cg                         the user.  If any are found, a warning message is
cg                         displayed, and the objects are displayed.

cg    congruent          Two geometric objects are congruent if they have the
cg                         same size and shape, and may be translated or rotated
cg                         to have the same position and orientation, such that
cg                         the difference between them is no more than the
cg                         estimated error in calculating that difference, based
cg                         on the tolerance limit TOL.
cg                         Objects that are mirror images, and can not be
cg                         superimposed, are not congruent.

cg    conic              See "conic sections".

cg    conic sections     The conic sections are the curves resulting from the
cg                         intersection of a plane with a circular cone.
cg                         The type of curve depends on the angle THETA of the
cg                         plane relative to the axis of the cone, and the
cg                         half-angle THHALF of the cone:
cg
cg                         hyperbola:  THETA = 0.
cg
cg                         parabola:   0 < THETA < THHALF.
cg
cg                         ellipse:    THHALF < THETA < 90 degrees.
cg
cg                         circle:     THETA = 90 degrees.

cg    conjugate          Conjugate complex numbers are pairs of complex numbers
cg                         of the form x + i*y and x - i*y, where i is the
cg                         square root of -1.
cg                         z  = x + i*y = r*exp( i*a) = r*cos(a) + i*r*sin(a),
cg                         z' = x - i*y = r*exp(-i*a) = r*cos(a) - i*r*sin(a).
cg                         where r = sqrt(x^2 + y^2), a = arctan(y / x),
cg                         x = r*cos(a), y = r*sin(a).
cg                         Note that the sum of the two conjugate complex
cg                         numbers is 2*x, while the product is x^2 + y^2.

cg    conjugate          In modular arithmetic, two numbers are conjugate if
cg                         they have the same value modulo the modulus.  That
cg                         is, they only differ by a multiple of the modulus.

cg    conjugate          On a hyperbola or hyperbolic cylinder, the conjugate
cg                         semiaxis is the line perpendicular to the transverse
cg                         semiaxis, from either of the two vertices to either
cg                         of the asymptotes of the hyperbola.  Its length is
cg                         half the distance between the asymptotes at the
cg                         vertex, in the direction of a tangent to the vertex.
cg                         See "transverse".
cg
cg                         For the hyperbola or hyperbolic cylinder,
cg                         QC + QXX * x^2 + QYY * y^2 = 0,
cg                         (QXX > 0, QYY < 0),
cg                         the length of the conjugate semiaxis is:
cg                         sqrt (QC / QXX), if QC > 0, and
cg                         sqrt (QC / QYY), if QC < 0.
cg
cg                         For the hyperboloid of one sheet,
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QC < 0, QXX => QYY > 0, QZZ < 0),
cg                         the length of the conjugate semiaxis is:
cg                         sqrt (QC / QZZ).
cg
cg                         For the hyperboloid of two sheets,
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QC > 0, QXX => QYY > 0, QZZ < 0),
cg                         the length of the conjugate semiaxis is:
cg                         sqrt (QC / QYY), in the plane x = 0, and
cg                         sqrt (QC / QXX), in the plane y = 0.

cg    constant           See "variable".

cg    constant           In data displayed for a quadric surface, the notation
cg                         "x const", "y const" or "z const" describes a plane
cg                         parallel to a major plane.  In data displayed for a
cg                         quadric curve, those notations describe a line
cg                         line perpendicular to a major axis.

cg    constants          See "internal" for GEOM internal numerical constants.

cg    construct          See "create".

cc    contfr             Command to find the integer coefficients of the
cc                         continued fraction for a specified value, and to
cc                         find the value of a continued fraction given the
cc                         coefficients (in any mode).
cc                         See "continued fraction".
cc
cc                         Command "contfr" relates to objects:  symbol,
cc                         variable.
cc
cc                         Forms include:
cc
ccin                       help contfr
ccin                       contfr [help]
cc
cc                           Display the command options.
cc
ccin                       contfr = VALUE
cc
cc                           Find the integer coefficients kc1, kc2, kc3, ...
cc                           of the continued fraction with value VALUE:
cc                           VALUE = kc1 + 1/(kc2 + 1/(kc3 + 1/(kc4 + ...))),
cc                           and the successive partial sums for VALUE, and
cc                           the integer numerators and denominators of the
cc                           corresponding rational fraction convergents.
cc                           If VALUE < 1, kc1 = 0.  Otherwise kc1 > 0.
cc                           All other coefficients > 0.
cc                           The coefficients of the continued fraction for 1/x
cc                           will differ from those of x only by a leading zero.
cc
cc                           The series will terminate when the relative
cc                           difference between successive partial sums is less
cc                           than TOL.  A very large final coefficient may
cc                           sometimes be ignored.
cc
ccin                       contfr C1 C2 C3 ... CN
cc
cc                           Find the value x of a continued fraction,
cc                           x = C1 + 1/(C2 + 1/(C3 + 1/(C4 + ...))), given
cc                           the coefficients C1, C2, C3, ... CN, which may be
cc                           integer or floating point, positive, zero or
cc                           negative.  Also find
cc                           the numerators and denominators of the rational
cc                           fraction convergents (when all coefficients are
cc                           integers) equivalent to the successive partial sums
cc                           of the continued fraction.
cc                           The method will fail if an infinity occurs.
cc                           Final coefficients of 0 will cause the values of
cc                           successive partial sums to oscillate, if they have
cc                           not already converged.
cc                           A final coefficient of 1 may be added to the
cc                           preceding coefficient.
cc
cc
cc                         See "continued fraction".
cc
cc                         Synonyms [contfr, cf], [help, h].

cg    continue           See "restart".

cg    continued          See "continued fraction".

cg    continued fraction
cg                       An expression of the form
cg                         x = C1 + 1/(C2 + 1/(C3 + 1/(C4 + ... 1/(CN))))...
cg                         where x > 0, and the coefficients are all positive
cg                         integers, except for C1, which is zero if x < 1.
cg                         If x is a rational number (an integer or a ratio of
cg                         two integers) the continued fraction terminates.
cg                         If x is an irrational number (a root of a polynomial
cg                         equation) the coefficients repeat in groups.
cg                         If x is a transcendental number (neither rational or
cg                         irrational, such as pi or e) the coefficients do not
cg                         repeat in groups, but may still form a predictable
cg                         pattern.
cg
cg                         To find the integer coefficients, start with the
cg                         integer part of x, find the reciprocal of the
cg                         remainder, and repeat.  See command "contfr".
cg
cg                         To evaluate a continued fraction, see "convergent",
cg                         "partial sum", command "contfr".
cg
cg                         If the first coefficient is zero, x is the reciprocal
cg                         of the x evaluated from the remaining coefficients.
cg
cg                         The final N coefficients may be replaced by a single
cg                         coefficient equal to the value x (not necessarily an
cg                         integer) of the continued fraction consisting of just
cg                         those N coefficients.
cg
cg                         Final coefficients of K, 1 may be replaced by K + 1.
cg
cg                         Golden Mean (n = 1) and Silver Means (n > 1):
cg                         the coefficients of the continued fraction with value
cg                         (n + sqrt (n^2 + 4)) / 2 are (n, n, n, n, ...)
cg                         for n = 1, 2, 3, ...
cg
cg                         A continued fraction solution for a root of the
cg                         quadratic equation P(x) = a + a*b * x - b * x^2 is
cg                           r1 = CF {a, b, a, b, a, b, ...}.
cg
cg                         See files cf.root and cf.size in ~edwards/geom/test

cg    contour            See "slice", "profile".

cg    control            See "control errors".

cg    control errors     To control typing errors, use command "undo", "redo"
cg                         or "indo", and see "input file".
cg                         To control numerical truncation errors, see "tol",
cg                         "error estimate".

cn    conv.mac           A macro file containing selected metric conversion
cn                         factors.  In directory ~edwards/work/geom/test .
cn                         To view or to read in conversion factors, use command
cn
cn                         input ~edwards/work/geom/test/conv.mac [options]
cn
cn                         See command "input" for options.

cg    conventions        See "command form", "default arguments", "key word",

cg    converge           See "convergence".

cg    convergence        Convergence of the iterative procedures used by
cg                         commands "side", "distance" and "proximal" is
cg                         determined by TOL.
cg                         The final relative change in distance must be no
cg                         greater than TOL, and the final angle between the
cg                         line from the specified point to the proximal point
cg                         and the normal vector of the quadric surface at the
cg                         proximal point must have a cosine within TOL of -1.0
cg                         or 1.0.

cg    convergent         The n'th convergent of a continued fraction is the
cg                         ratio of integers obtained by evaluating only the
cg                         first n coefficients of the continued fraction.
cg                         The value of the n'th convergent is the n'th
cg                         partial sum.
cg
cg                         To find the n'th convergent P(n) / Q(n), and the
cg                         n'th partial sum x(n), given the coefficients
cg                         C(n), n = 1, N:
cg                           P(0) = 1,            P(1) = C(1),
cg                           P(n) = C(n) * P(n-1) + P(n-2), n = 2, N,
cg                           Q(0) = 0,            Q(1) = 1,
cg                           Q(n) = C(n) * Q(n-1) + Q(n-2), n = 2, N,
cg                           x(n) = P(n) / Q(n), n = 2, N.
cg
cg                         These values are found and displayed when command
cg                         "contfr" is used.

cg    conversion         See "conversion factors", "coordinate conversion",
cg                         "convert output", "unit conversion",
cg                         "vector conversion".

cg    conversion factors
cg                       Selected metric conversion factors are in macro file
cg                         conv.mac in directory ~edwards/work/geom/test .

cg    convert            See "conversion factors", "coordinate conversion",
cg                         "convert output", "unit conversion",
cg                         "vector conversion".

cg    convert output     To convert the output file(s) (geom_hsp or the file(s)
cg                         specified by the user with command "output") to an
cg                         input file, see "input file".

cc    COORD              In command "plot", option "axis", the coordinate to be
cc                         plotted on the horizontal or vertical axis.  Must be
cc                         x, y, z, rcyl, rsph, theta or phi.  See commands
cc                         "coordinate", "angles".

cc    coord              A synonym for coordinate.

cg    coordinate         A value used to locate a mesh point in the mesh or
cg                         to locate a physical point in a physical space.
cg                         See "coordinate system", command "search".

cc    coordinate         An option in command "debug", to display GEOM internal
cc                         variables for the coordinate system and angles:
cc                         asys, acoordu, acoordv, acoordw, angunit.
cc                         Synonyms:  [coordinate, coord, cs, sys, system],

cc    coordinate         Command to display or specify the coordinate system of
cc                         the physical space.  See "coordinate conversion",
cc                         "coordinate system", "vector conversion", "angle".
cc                         Display of point coordinates and vector components
cc                         will be in the specified coordinate system, unless
cc                         specifically labeled otherwise, e.g., xyz.
cc                         Specification of point coordinates and vector
cc                         components must be in the specified coordinate
cc                         system.
cc                         Note:  variables are not affected by changes
cc                         in the coordinate system or angle units, so their
cc                         values and units remain as intended by the user when
cc                         originally specified.  Variables may be assigned a
cc                         descriptive tag to specify the units or to provide
cc                         other information.  See command "variable", option
cc                         "tag".
cc
cc                         Forms include:
cc
ccin                       help coordinate
ccin                       coordinate help
cc
cc                           Display the command options.
cc
ccin                       coordinate
cc
cc                           Display the coordinate system.
cc
ccin                       coordinate cartesian
cc
cc                           Set the coordinate system to rectangular (x, y, z).
cc
ccin                       coordinate cylindrical
cc
cc                           Set the coordinate system to cylindrical (rcyl,
cc                           theta, z).
cc
ccin                       coordinate spherical
cc
cc                           Set the coordinate system to spherical (rsph,
cc                           theta, phi).
cc
cc                         See command "angles" to specify the angle units.
cc
cc                         Synonyms:  [coordinate, coord, cs, sys, system],
cc                         [cartesian, Cartesian, cart, rectangular, rect, xyz],
cc                         [cylindrical, cyl], [help, h], [spherical, sph].

cg    coordinate         See "coordinate conversion", "coordinate surface",
cg                         "coordinate system", "surface of coord".

cg    coordinate conversion
cg                         To convert the coordinate system of existing points
cg                         and/or vectors, use commands "coordinate" and
cg                         "angles" to specify a new coordinate system, and
cg                         display the points and/or vectors with commands
cg                         "point" and "vector".  See "coordinate system",
cg                         "vector conversion".
cg                         Angles may be in degrees or radians.  See "angle".
cg
cg                         To convert the coordinate system of points and/or
cg                         vectors that appear in a data display, but are not
cg                         saved, see "(xyz)".
cg
cg                         rectangular (x, y, z):
cg                           x = rcyl * cos (theta),
cg                           x = rsph * cos (theta) * sin (phi),
cg                           y = rcyl * sin (theta),
cg                           y = rsph * sin (theta) * sin (phi),
cg                           z = rsph * cos (phi).
cg
cg                         cylindrical (rcyl, theta, z):
cg                           rcyl^2  = x^2 + y^2,
cg                           rcyl    = rsph * sin (phi),
cg                           theta   = arctan (y / x)        (azimuth angle),
cg                           sin (theta) = y / sqrt (x^2 + y^2),
cg                           cos (theta) = x / sqrt (x^2 + y^2),
cg                           tan (theta) = y / x.
cg
cg                         spherical (rsph, theta, phi):
cg                           rsph^2 = x^2 + y^2 + z^2,
cg                                   = rcyl^2 + z^2,
cg                           theta   = arctan (y / x)        (azimuth angle),
cg                           cos (theta) = x / sqrt (x^2 + y^2),
cg                           sin (theta) = y / sqrt (x^2 + y^2),
cg                           phi     = arccos (z / rsph)     (polar angle
cg                                   = arctan (rcyl / z)      from z axis),
cg                           sin (phi) = sqrt (x^2 + y^2) /
cg                                       sqrt (x^2 + y^2 + z^2),
cg                           sin (phi) = rcyl / sqrt (rcyl^2 + z^2),
cg                           cos (phi) = z / sqrt (x^2 + y^2 + z^2),
cg                           cos (phi) = z / sqrt (rcyl^2 + z^2),
cg                           tan (phi) = sqrt (x^2 + y^2) / z,
cg                           tan (phi) = rcyl / z.
cg
cg                         Note:  to avoid numerical error and insure that
cg                         all conversion are reversible, add 10^99 to x,
cg                         rcyl and rs, replace all sines and cosines less
cg                         than TOL with zero, and replace any results with
cg                         an estimated relative error less than TOL with zero.

cg    coordinate surface
cg                       A coordinate surface is a surface at a constant value
cg                         of one of the three coordinates of an orthogonal
cg                         coordinate system, such as rectangular (x, y z),
cg                         cylindrical (rcyl, theta, z) or spherical (rsph,
cg                         theta, phi).  To create a coordinate surface,
cg                         see "x plane", "y plane", "z plane", "rcyl cylinder",
cg                         "theta plane", "rsph sphere", "phi cone".
cg
cg                         To specify the coordinate system and the angle units,
cg                         use commands "coordinate" and "angles".
cg
cg                         To create a volume element bounded by coordinate
cg                         surfaces, use command "brick".
cg
cg                         To create a 3-D array of points on a specified family
cg                         of coordinate surfaces, use command "brick", followed
cg                         by command
cg                         "point PMESH brick BRNAME mesh block [volume]".
cg                         See "briquette".
cg
cg                         To create a family of variables whose values
cg                         are an arithmetic or geometric series, for use in
cg                         specifying coordinates, use command "variable",
cg                         option "series".

cg    coordinate system
cg                       The coordinate system used to specify the coordinates
cg                         of points is specified with command "coordinate",
cg                         and may be one of the following:
cg
cg                         Rectangular (x, y, z):
cg                           x = rcyl * cos (theta),
cg                           x = rsph * cos (theta) * sin (phi),
cg                           y = rcyl * sin (theta),
cg                           y = rsph * sin (theta) * sin (phi),
cg                           z = rsph * cos (phi).
cg
cg                         Cylindrical (rcyl, theta, z):
cg                           rcyl^2  = x^2 + y^2,
cg                           rcyl    = rsph * sin (phi),
cg                           theta   = arctan (y / x),
cg                             (azimuth angle around z axis, measured
cg                              counterclockwise from x axis).
cg
cg                         Spherical (rsph, theta, phi):
cg                           rsph^2 = x^2 + y^2 + z^2,
cg                                   = rcyl^2 + z^2,
cg                           theta   = arctan (y / x),
cg                           phi     = arccos (z / rsph),
cg                                   = arctan (rcyl / z),
cg                             (polar angle from positive z axis).
cg
cg                         For practical reasons, the coefficients of the
cg                         implicit equations for quadric surfaces are always
cg                         based on a rectangular (x, y, z) coordinate system.
cg
cg                         See "coordinate conversion", "vector conversion".

cg    coordinates        See "coordinate conversion", "coordinate",
cg                         "vector conversion".

cg    copy               See "copy objects".

cc    copy               Command to copy an alias, marker, variable, vector,
cc                         tensor operator, point, cluster, line, triangle,
cc                         regular polygon, annular disk, quadric surface
cc                         (including a plane, sphere, circular cylinder,
cc                         circular cone, hyperbolic paraboloid, ellipsoid,
cc                         axially symmetric quadric surface or general quadric
cc                         surface), regular polyhedron, tetrahedron, brick,
cc                         zone, probability bin, probability distribution
cc                         function (pdf), symbol or big integer.
cc                         You can not copy over an existing object.
cc                         The copy must not have the same name as the original.
cc                         This is an excellent way to create a backup before
cc                         modifying an object, in case of an error.
cc                         Note:  no replacement of symbols will be done
cc                         in the command "copy symbol ...".
cc
cc                         Command "copy" relates to objects:  alias, axisym
cc                         big, bin, brick, cluster, cone, cylinder, disk,
cc                         ellipsoid, hyperb, line, marker, operator, pdf,
cc                         plane, point, polygon, polyhedron, quadric, sphere,
cc                         symbol, tetrahedron, triangle, variable, vector,
cc                         zone.
cc
cc                         Forms include:
cc
ccin                       help copy
ccin                       copy [help]
cc
cc                           Display the command options.
cc
cc                         In the following command, use "+" or "-" instead of
cc                         OBJNAME2 to form the name by incrementing or
cc                         decrementing the base name for objects of type
cc                         OBJTYPE (which may not be OBJNAME).
cc                         See command "last", "increment names".
cc
ccin                       copy OBJTYPE OBJNAME OBJNAME2
cc
cc                           Copy object type OBJTYPE (alias, axisym, big, bin,
cc                           brick, cluster, cone, cylinder, disk, ellipsoid,
cc                           hyperb, line, marker, operator, pdf, plane, point,
cc                           polygon, polyhedron, quadric, sphere, symbol,
cc                           tetrahedron, triangle, variable, vector, zone)
cc                           with name OBJNAME to the same object type with name
cc                           OBJNAME2.
cc                           No copy will be made if OBJTYPE is symbol or alias.
cc
cc                         The command above may be placed between commands "do"
cc                         and "enddo", to create a do loop over subscripted
cc                         object names, to copy all of them to new names.
cc
cc                         Synonyms:  [alias, al, a,], [brick, br],
cc                         [cluster, cl], [copy, cp, dup, duplicate],
cc                         [cylinder, cyl], [disk, disc, dk],
cc                         [ellipsoid, el, ell, ellipse], [help, h],
cc                         [hyperb, saddle], [line, l, ln], [marker, mark, m],
cc                         [operator, oper, op], [plane, pl],
cc                         [point, pnt, pt, p], [polygon, polyg, pg],
cc                         [polyhedron, polyh, ph], [quadric, quad, q],
cc                         [sphere, sph], [symbol, sym, symb],
cc                         [tetrahedron, tetra, tet], [triangle, tri],
cc                         [variable, var, set, s], [vector, v, vect],
cc                         [zone, z, zn].

cg    copy objects       See command "copy".  See "cones", "cylinders",
cg                         "planes", "quadric families", "quadric surfaces",
cg                         "spheres".
cg                         To copy the output from a command for use in a new
cg                         command, see "cut and paste".

cc    cos                A synonym for cosine, in commands "project" and
cc                         "vector".

cc    cos                An option in command "project", when projecting onto
cc                         the surface of a circular cylinder, to make the axial
cc                         distance of each point from point PCEN on the axis
cc                         equal to the cosine of the original polar angle phi
cc                         of the point, as measured relative to point PCEN,
cc                         in the positive direction along the axis.

cc    cos                An option in command "variable", argument FUNCTION,
cc                         to indicate the trigonometric cosine function.
cc                         A cos B means A * cos (B).

cf    cos                The trigonometric cosine function.
cf                         Example:  y = cos (x) means y is the cosine of x.
cf                         x must be in radians.

cc    cosh               An option in command "variable", argument FUNCTION,
cc                         to indicate the hyperbolic cosine function.
cc                         A cosh B means A * cosh (B).

cf    cosh               The hyperbolic cosine function.  Example:  y = cosh (x)
cf                         means y = (1/2) * (e^x + e^(-x)).

cc    cosine             An option in command "vector", to create a vector by
cc                         randomly sampling from a cosine-power distribution
cc                         around a specified axis vector VAXIS, with a
cc                         specified power POWER.
cc
cc                         An option in command "project", to project onto the
cc                         surface of a circular cylinder by replacing the axial
cc                         distance of a point from the center of the cylinder
cc                         with the cosine of the polar angle phi of the
cc                         point, to preserve relative areas determined from
cc                         points projected from a spherical surface centered
cc                         at the center of the cylinder.  A special projection
cc                         used in cartography.
cc
cc                         Synonyms:  [cosine, cos].

cg    cosine             To find the cosine of the angle between two vectors,
cg                         use command "dot".
cg                         Also see "cosine-power", "Law of Cosines".

cg    cosine-power       A cosine-power distribution is one in which a power
cg                         of the cosine of the angle from a specified axis
cg                         is uniformly distributed from 0 to 1, and all angles
cg                         are within 90 degrees of the positive axial
cg                         direction.
cg
cg                         For an isotropic distribution the power must be zero.
cg
cg                         For a cosine distribution, the power must be 1.
cg
cg                         For distributions more strongly peaked toward the
cg                         axis, the power must be larger than 1.
cg
cg                         For a unit vector randomly sampled from a general
cg                         cosine-power distribution, with a power POWER from
cg                         zero to infinity, the relationship between POWER and
cg                         the expected value <ua> of the axial component of the
cg                         vector is as follows:
cg
cg                           <ua>  = 1 -  1 / (POWER + 2)
cg                           POWER = 1 / (1 - <ua>) - 2
cg
cg                           <ua>        POWER   angle (degrees)
cg                           0.5            0        60.00
cg                           2/3            1        48.19
cg                           0.8            3        36.87
cg                           0.9            8        25.84
cg                           0.99          98         8.11
cg                           0.999        998         2.56
cg                           0.9999      9998         0.81
cg                           0.99999    99998         0.26

cg    count              If you need to count the number of times a command is
cg                         repeated, initialize a variable to zero, then
cg                         increment it each time the command is repeated.
cg
cg                         variable ntot [=] 0
cg
cg                           Initialize ntot to zero.
cg
cg                         alias t = "variable ntot = ntot + 1 ; COMMAND"
cg
cg                           Create alias "t" to increment ntot and do COMMAND.
cg
cg                         t
cg
cg                           Increment ntot and do command COMMAND.
cg
cg                         Any block of commands such as those above may be
cg                         executed together in several ways.  See "alias",
cg                         "macro", "saved input lines", "shortcuts".

cc    cp                 A synonym for copy.

cg    cpar               In columns 1-4 of geom_base, indicates a parameter.

cg    CPU                Central processing unit.  In the time summary at the
cg                         end of the run, a component of machine time use,
cg                         separate from input/output (I/O) and system (SYS)
cg                         time.

cn    craps.mac          A macro file to create a pdf representing rolling two
cn                         dice, to demonstrate how to work with bins and pdfs.
cn                         In ~/work/geom/test .

cg    create             To describe an environmental, operational, geometric,
cg                         or Monte Carlo object, using a command.
cg                         See "create objects", "create environment",
cg                         "create operators".

cg    create             See "create environment", "create Monte Carlo",
cg                         "create objects", "create operators".

cg    create environment
cg                       The commands for modifying the default values of
cg                         certain environmental parameters are:
cg                         alias, marker, angles, coordinate, delimiter, icalc,
cg                         input, output, plot, tol.

cg    create Monte Carlo
cg                         The commands for creating Monte Carlo objects are:
cg                         bin (probability bins) and pdf (probability
cg                         distribution functions).
cg                         Also see "random", "sample", "spin".

cg    create objects     Geometric objects are created with commands:
cg                         point, cluster, line, vector, triangle, polygon,
cg                         disk, plane, sphere, cylinder, cone, hyperb,
cg                         ellipsoid, axisym, quadric, polyhedron, tetrahedron,
cg                         brick, zone.
cg
cg                         Other objects are created with commands "alias",
cg                         "bin", "marker", "operator", "pdf", "symbol",
cg                         "variable".
cg
cg                         The commands for creating objects have the general
cg                         forms:
cg
cg                         OBJTYPE [OBJNAME,+,-] [various specifications]
cg
cg                           Create one or more objects of type OBJTYPE with
cg                           initial name [OBJNAME, or the name incremented or
cg                           decremented from the base name for this object
cg                           type], with various specifications.
cg                           Names of objects after the first object will be
cg                           incremented in ASCII sequence.
cg
cg                         copy OBJTYPE OBJNAME [OBJNAME2,+,-]
cg
cg                           Copy the object of object type OBJTYPE with name
cg                           OBJNAME to object [OBJNAME2, or the name
cg                           incremented or decremented from the last name
cg                           specified for an object of this type].
cg
cg                         rename OBJTYPE OBJNAME [OBJNAME2,+,-]
cg
cg                           Rename the object of object type OBJTYPE with name
cg                           OBJNAME to object [OBJNAME2, or the name
cg                           incremented or decremented from the last name
cg                           specified for an object of this type].
cg
cg                         rename OBJTYPE OBJNAME OBJNAME2 array
cg
cg                           Rename the object of object type OBJTYPE by
cg                           replacing the subscripted stem name OBJNAME with
cc                           the subscripted stem name OBJNAME2.
cg
cg                         delete OBJTYPE [OBJNAME,all]
cg
cg                           Delete the object of object type OBJTYPE [with name
cg                           OBJNAME, or all such objects].
cg
cg                         See "OBJTYPE", "OBJNAME".

cg    create operators   Operators are created with commands:  variable, vector,
cg                         operator.

cg    cross              See "cross product", command "cross".

cc    cross              Command to find the cross (outer) product of two
cc                         vectors, which has a magnitude equal to the area of
cc                         the parallelogram specified by the two vectors, or
cc                         twice the area of the triangle specified by the two
cc                         vectors.
cc
cc                         Command "cross" relates to objects:  symbol, vector.
cc
cc                         Forms include:
cc
ccin                       help cross
ccin                       cross [help]
cc
cc                           Display the command options.
cc
ccin                       cross VNAME1 VNAME2
cc
cc                           Find the vector which is the cross (outer) product
cc                           of vectors VNAME1 and VNAME2.
cc
cc                         The cross product may be saved as another vector:
cc
cc                         vector VNAME cross VNAME1 VNAME2
cc
cc                           Create vector VNAME, the cross (outer) product of
cc                           vectors VNAME1 and VNAME2.
cc
cc                         Synonyms:  [cross, outer], [help, h].

cc    cross              An option in command "vector", to create a vector which
cc                         is the cross product of two vectors.

cg    cross product      The cross (or outer or vector) product of two vectors
cg                         A = (AX, AY, AZ) and B = (BX, BY, BZ) is the vector
cg                         C = A cross B = (CX, CY, CZ), where
cg                         C = (AY*BZ - AZ*BY, AZ*BX - AX*BZ, AX*BY - AY*BX).
cg                         |C| = |A| * |B| * sin (THETA), where THETA is the
cg                         angle between vectors A and B.
cg                         Note that B cross A = -(A cross B), and that the
cg                         cross product of two parallel vectors is zero.

cc    crt                Command to solve the Chinese Remainder Theorem for
cc                         a specified set of integer divisors and remainders,
cc                         or to find the remainders for a specified integer
cc                         value, using the first few prime numbers as divisors,
cc                         or with a specified set of relatively prime
cc                         divisors.  See command "factor".
cc
cc                         Command "crt" relates to objects:  symbol, variable.
cc
cc                         Forms include:
cc
ccin                       help crt
ccin                       crt [help]
cc
cc                           Display the command options.
cc
ccin                       crt IDIV1 IREM1 IDIV2 IREM2 ... IDIVN IREMN
cc
cc                           Find the least integer value that has the
cc                           remainders IREM1, IREM2, ..., IREMN when divided
cc                           by the integer divisors IDIV1, IDIV2, ..., IDIVN,
cc                           respectively, where the integer divisors are 2 or
cc                           more, and have no common factor.  Also display the
cc                           next four higher integer values with the same
cc                           remainders, if less than 10^18.
cc
ccin                       crt = IVAL
cc
cc                           Find the remainders resulting from dividing the
cc                           integer IVAL by the first few prime numbers
cc                           (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, ...),
cc                           using the minimum set of prime numbers for which
cc                           IVAL is the least integer with the same remainders.
cc                           IVAL must be 2 or more.
cc
ccin                       crt = IVAL IDIV1 IDIV2 ... IDIVN
cc
cc                           Find the remainders resulting from dividing the
cc                           integer IVAL by the integers IDIV1, IDIV2, ...,
cc                           IDIVN, which must be 2 or more, and have no common
cc                           factors.  IVAL must be 2 or more.
cc
cc                         Synonyms:  [help, h].

cg    cryptography       See command "big".

cc    cs                 A synonym for coordinate.

cg    cube               A cube is a regular polyhedron with 8 vertices,
cg                         12 edges and 6 square faces.
cg                         The edge length, face area, volume, radius of
cg                         inscribed sphere, dihedral angle and central edge
cg                         angle, for a circumscribed sphere radius of 1.0 are:
cg
cg                         edge    = 2.0 / sqrt (3.0)        = 1.154700538379
cg                         area    = 4.0 / 3.0               = 1.333333333333
cg                         volume  = 8.0 * sqrt (3.0) / 9.0  = 1.539600717839
cg                         rinsc   = 1.0 / sqrt (3.0)        = 0.5773502691896
cg                         angdih  = acos (0.0)              = 90.00000000000
cg                         angcent = acos (1.0 / 3.0)        = 70.52877936551
cg
cg                         See "polyhedron", "brick".

cg    cubic              See command "roots".

cg    cubic              A cubic polynomial equation in z = x + i*y, where z is
cg                         real or complex, x and y are real, and i = sqrt (-1):
cg                           P(z) = a0 + a1*z + a2*z^2 + a3*z^3 = 0,
cg                         with real coefficients a0, a1, a2 and a3 = 1, has
cg                         three roots r1, r2, r3, of which one or three are
cg                         real, has two extrema (maxima and minima) e1, e2 of
cg                         which either zero or two are real, and has one real
cg                         inversion point v1.
cg                         The roots satisfy P(z) = 0.  The extrema satisfy
cg                         P'(z) = 0.  The inversion points satisfy P''(z) = 0.
cg                         P' and P'' are the first and second derivatives of
cg                         P with respect to z.
cg                         Some interesting relationships between the
cg                         coefficients and the properties of the polynomial
cg                         are as follows:
cg                          -a0     = r1*r2*r3
cg                           a1 / 3 = (1/3)*(r1*r2 + r2*r3 + r3*r1)
cg                                  = e1*e2
cg                          -a2 / 3 = (1/3)*(r1 + r2 + r3)
cg                                  = (1/2)*(e1 + e2)
cg                                  = v1
cg                           a3     = 1
cg
cg                         Note that the inversion point v1 is at the average z
cg                         value of the roots and the extrema, and that the
cg                         average value of the products of pairs of roots and
cg                         extrema are the same.
cg
cg                         See command "roots".

cg    curly bracket      The left or right curly bracket, "{" or "}".

cc    curt               An option in command "variable", argument FUNCTION,
cc                         to indicate the real cube root function.
cc                         A curt B means A * B^(1/3).

cf    curt               The cube root function.  Example:  y = curt (x) means
cf                         y = x^(1/3) (real value only).
cf
cf                         To find the real and complex cube roots of any
cf                         real nonzero number B, use command:
cf
cf                         roots B 0 0 -1

cg    curvature          The curvature of a curve is the inverse of its radius
cg                         of curvature.  See "radius of curvature",
cg                         "principal radius".
cg                         See commands "arc", "extrema".

cg    curve              See "quadric curve", "intersection curve", outline.

cc    cut                A synonym for slice.

cg    cut                See "cut and paste", "triangle cutting".

cg    cut and paste      If you have a mouse with cut and paste capability, you
cg                         can create variables, points, vectors, etc., by
cg                         cutting and pasting the output from previous commands
cg                         for use as the arguments of the new commands.
cg                         Note that the precision variable TOL should not be
cg                         less than the precision of command arguments.

cc    cute               Command to find all triangles formed by extending any
cc                         two sides of a specified triangle, to add a section
cc                         with the same perimeter and area as the specified
cc                         triangle.  See "cutting line", "triangle cutting",
cc                         and commands "cuts", "trig" and "triangle".
cc
cc                         Command "cute" relates to objects:  symbol, variable.
cc
cc                         Forms include:
cc
ccin                       help cute
ccin                       cute [help]
cc
cc                           Display the command options.
cc
ccin                       cute VA VB VC
cc
cc                           Find each triangle that can be formed by extending
cc                           any two edges of the triangle with edges VA, VB and
cc                           VC, to add a section with the same perimeter and
cc                           area as the original triangle.  This is the inverse
cc                           of command "cuts".
cc
cc                         Synonyms:  [help, h].

cc    cuts               Command to find each straight line that cuts a triangle
cc                         into two parts with equal perimeters and areas.
cc                         See "cutting line", "triangle cutting", and commands
cc                         "cute", "trig" and "triangle".
cc
cc                         Command "cuts" relates to objects:  symbol, variable.
cc
cc                         Forms include:
cc
ccin                       help cuts
ccin                       cuts [help]
cc
cc                           Display the command options.
cc
ccin                       cuts VA VB VC
cc
cc                           Find each straight line that cuts the triangle with
cc                           edges VA, VB and VC into two sections with equal
cc                           perimeters and areas, and display the edges cut,
cc                           the fractional and absolute distances of the ends
cc                           of the cutting line along the edges from their
cc                           common vertex, and the length of the cutting line.
cc                           There may be 1, 2 or 3 such cutting lines.
cc                           This is the inverse of command "cute".
cc
cc                         Synonyms:  [help, h].

cg    cutting            See "cutting line", "triangle cutting".

cg    cutting line       To partition a triangle into two parts of equal area
cg                         and equal perimeter with straight line cuts, see
cg                         "triangle cutting", commands "cute", "cuts",
cg                         "triangle", and "trig".
cg                         The cutting lines will be displayed whenever a
cg                         triangle is created or displayed.

cg    cx                 In columns 1-2 of geom_base, indicates an executable
cg                         program.

cc    cyl                A synonym for cylinder.

cc    cyl                A synonym for cylindrical in command "project".

cc    CYL(1)             In command "cylinder", the name of a base cylinder,
cc                         used to create a family of cylinders.

cg    cylinder           A cylinder is a surface in 3-D space described by an
cg                         implicit quadric equation, and is a limit case of a
cg                         hyperboloid of one sheet or an ellipsoid.
cg                         At any point in the surface, any line drawn parallel
cg                         to the cylindrical axis and perpendicular to the
cg                         normal vector, lies entirely within the surface.
cg                         Along with planes, cones, hyperbolic paraboloids and
cg                         hyperboloids of one sheet, a cylinder is a ruled
cg                         surface.
cg
cg                         The standard forms of the implicit equations for
cg                         cylinders are as follows (each coefficient must have
cg                         the preceding sign):
cg
cg                         Parabolic cylinder:                -QY*y + x^2 = 0
cg                         Hyperbolic cylinder:
cg                                                1 + QXX*x^2 - |QYY|*y^2 = 0
cg                         Real elliptic cylinder:
cg                                                - 1 + QXX*x^2 + QYY*y^2 = 0
cg                         Real circular cylinder:
cg                                                - 1 + QXX * (x^2 + y^2) = 0
cg                                              or        x^2 + y^2 =  rcyl^2
cg                         Imaginary elliptic cylinder:
cg                                                  1 + QXX*x^2 + QYY*y^2 = 0
cg                         Imaginary circular cylinder:
cg                                                  1 + QXX * (x^2 + y^2) = 0
cg                                               or       x^2 + y^2 = -rcyl^2
cg
cg                         The word "cylinder" in a command means a real
cg                         circular cylinder.  Otherwise, use "quadric".
cg
cg                         To find the distance from a cylinder to a point, use
cg                         command "distance", "proximal" or "side".
cg
cg                         To find the distance from a circular cylinder to a
cg                         point, use command "distance".
cg                         To find the distance and proximal point, and/or the
cg                         intersections of a circular cylinder and a line,
cg                         a triangle, plane, a sphere or another circular
cg                         cylinder, use command "distance".
cg
cg                         To find the distance or intersection between a plane
cg                         and a general cylinder, use command "distance".
cg
cg                         The following commands relate to circular
cg                         cylinders:
cg                         accelerate, arc, axisym, copy, cylinder, debug,
cg                         delete, distance, extrema, help, invert, last, list,
cg                         move, operator, point, project, proximal, quadric,
cg                         reflect, rename, repack, rotate, scale, search, side,
cg                         slice, sort, symbol, synonym, tables, track, triple,
cg                         vector, zone.
cg
cg                         Also see "rcyl cylinder".

cc    cylinder           In a command, means a circular cylinder, except in
cc                         command "cylinder", option "scale", when a linear or
cc                         radial scaling operator with an axis not parallel to
cc                         that of the base cylinder can create an elliptic
cc                         cylinder.

cc    cylinder           Command to display or create circular cylinders (except
cc                         that linear or radial scaling may create elliptic
cc                         cylinders).  Creating a cylinder replaces any
cc                         existing quadric surface having the same name.
cc                         The normal vectors will be pointed radially outward.
cc                         See "quadric" for other options.
cc                         See "do loop use".
cc
cc                         Command "cylinder" relates to objects:  axisym,
cc                         cylinder, operator, point, quadric, symbol, variable,
cc                         vector.
cc
cc                         Forms include:
cc
ccin                       help cylinder
ccin                       cylinder [help]
cc
cc                           Display the command options.
cc
ccin                       cylinder [all,list]
cc
cc                           Display all circular cylinders (short display).
cc
ccin                       cylinder list CYLNAME1 CYLNAME2 CYLNAME3 ...
cc
cc                           Display circular cylinders CYLNAME1, CYLNAME2,
cc                           CYLNAME3, ..., with or without subscripts (short
cc                           display).
cc
ccin                       cylinder CYLNAME
cc                           Display circular cylinder CYLNAME (long display.
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         CYLNAME or CYL(2) to form the name by incrementing or
cc                         decrementing the base name for circular cylinders.
cc                         See command "last", "increment names".
cc
ccin                       cylinder CYLNAME = PAXIS VAXIS RADIUS
cc
cc                           Create circular cylinder CYLNAME, with an axis
cc                           through point PAXIS in the direction of vector
cc                           VAXIS, and radius RADIUS.
cc
ccin                       cylinder CYLNAME fit VAXIS PNAME1 PNAME2 PNAME3
cc
cc                           Create circular cylinder CYLNAME with axis vector
cc                           VAXIS, through the three points PNAME1, PNAME2 and
cc                           PNAME3, which must not be coincident or collinear.
cc
ccin                       cyl CYLNAME conc NUMCYL INC PAXIS VAXIS RAD1 RAD2
cc
cc                           Create a family of NUMCYL concentric circular
cc                           cylinders CYLNAME, ..., with names incremented by
cc                           INC characters, with an axis through point PAXIS in
cc                           the direction of vector VAXIS, and with radii
cc                           equally spaced from radius RAD1 to radius RAD2.
cc                           See "increment names".
cc                           Note:  "cyl" is a synonym for "cylinder".
cc                           Note:  "conc" is a synonym for "concentric".
cc
cc                           This command can be replaced by using commands
cc                           "do" and "enddo" to create a do loop over any
cc                           of the "cyl" commands, using subscripted cylinder
cc                           names, with more general specifications.
cc
ccin                       cylinder CYL(2) move NUMCYL INC CYL(1) VMOVE
cc
cc                           Create a family of NUMCYL circular cylinders
cc                           CYL(2), ..., with names incremented by INC
cc                           characters, and spaced at intervals of vector
cc                           VMOVE, starting from circular cylinder CYL(1).
cc                           See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
cc
ccin                       cylinder CYL(2) rotate NUMCYL INC CYL(1) OPNAME PINV
cc
cc                           Create a family of NUMCYL circular cylinders
cc                           CYL(2), ..., with names incremented by INC
cc                           characters, by rotating the preceding cylinder with
cc                           operator OPNAME and invariant point PINV, starting
cc                           from circular cylinder CYL(1).
cc                           See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       cylinder CYL(2) scale NUMCYL INC CYL(1) OPNAME PINV
cc
cc                           Create a family of NUMCYL cylinders CYL(2), ...,
cc                           with names incremented by INC characters, by
cc                           scaling the preceding cylinder with operator OPNAME
cc                           and invariant point PINV, starting from circular
cc                           cylinder CYL(1).  WARNING:  a linear or radial
cc                           scaling axis not parallel to that of CYL(1) will
cc                           produce elliptic cylinders.  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
cc                         Synonyms:  [help, h], [concentric, conc],
cc                         [cylinder, cyl], [move, mv, trans, translate],
cc                         [rotate, rot].

cc    cylinder           An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on one or more circular
cc                         cylinders.
cc                         Synonyms:  [cylinder, cyl].

cc    cylinder           An option in command "project", to project onto the
cc                         surface of a circular cylinder.

cg    cylinder           See "cylinder, circular", "cylinder, elliptic",
cg                         "cylinder, hyperbolic", "cylinder, parabolic".

cg    cylinder arrays    Cylinders may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    cylinder, circular
cg                       For the circle or circular cylinder:
cg                         QC + QXX * x^2 + QYY * y^2 = 0, for all z,
cg                         (QC < 0, QXX = QYY > 0),
cg                         the center is at x = 0, y = 0,
cg                         the main axis is the z axis, and
cg                         the radius is RCYL = sqrt (-QC / QXX).
cg
cg                         The standard equation for the circle or circular
cg                         cylinder is x^2 + y^2 = RCYL^2.

cg    cylinder, elliptic
cg                       For the ellipse or elliptic cylinder:
cg                         QC + QXX * x^2 + QYY * y^2 = 0, for all z,
cg                         (QC < 0, QXX => QYY > 0),
cg                         the center is at x = 0, y = 0,
cg                         the main axis is the z axis,
cg                         the major semiaxis is A = sqrt (-QC / QYY),
cg                         the minor semiaxis is B = sqrt (-QC / QXX),
cg                         the eccentricity is sqrt (1 - QYY / QXX) < 1,
cg                         or sqrt (1 - (B / A)^2) < 1,
cg                         the two foci are at:
cg                         x = 0, y = (+/-)sqrt (QC / QXX - QC / QYY),
cg                         or y + (+/-)sqrt (B^2 - A^2),
cg                         the distance from the center to a focus is
cg                         sqrt (QC / QXX - QC / QYY), or sqrt (B^2 - A^2), and
cg                         the length of the latus rectum (width at focus) is
cg                         2 * sqrt (-QC * QYY) / QXX or 2 * B^2 / A.
cg
cg                         The standard equation for the ellipse or elliptic
cg                         cylinder is (x / B)^2 + (y / A)^2 = 1, for all z.

cg    cylinder, hyperbolic
cg                         For the hyperbola or hyperbolic cylinder:
cg                         QC + QXX * x^2 + QYY * y^2 = 0, for all z,
cg                         (QXX > 0, QYY < 0),
cg                         the center is at x = 0, y = 0,
cg                         the length of the transverse semiaxis is
cg                         A = sqrt (-QC / QYY), if QC > 0, and
cg                         A = sqrt (-QC / QXX), if QC < 0.
cg                         the length of the conjugate semiaxis is
cg                         B = sqrt (QC / QXX), if QC > 0, and
cg                         B = sqrt (QC / QYY), if QC < 0.
cg                         the main axis is the z axis,
cg                         the eccentricity is
cg                         sqrt (1 - QYY / QXX) > 1, if QC > 0, or
cg                         sqrt (1 - QXX / QYY) > 1, if QC < 0, or
cg                         sqrt (1 + (B / A)^2),
cg                         the two foci are at
cg                         x = 0, y = (+/-)sqrt (QC / QXX - QC / QYY),
cg                         or     y = (+/-)sqrt (A^2 + B^2), (QC > 0),
cg                         y = 0, x = (+/-)sqrt (QC / QYY - QC / QXX),
cg                         or     x = (+/-)sqrt (A^2 + B^2), (QC < 0),
cg                         the distance from the center to a focus is
cg                         sqrt (abs (QC / QXX - QC / QYY)), or
cg                         sqrt (A^2 + B^2), and
cg                         the length of the latus rectum (width at focus) is
cg                          2 * sqrt (-QC * QYY) / QXX, (QC > 0), or
cg                         -2 * sqrt (-QC * QXX) / QYY, (QC < 0), or
cg                         2 * B^2 / A.
cg                         The standard equation for the hyperbola or hyperbolic
cg                         cylinder is
cg                         (x / B)^2 - (y / A)^2 = 1, (QC < 0), or
cg                         (y / A)^2 - (x / B)^2 = 1, (QC > 0), for all z.

cg    cylinder arrays    Cylinders may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    cylinder, parabolic
cg                         For the parabola or parabolic cylinder:
cg                         QY * y + QXX * x^2 = 0, for all z,
cg                         the center is the vertex at x = 0, z = 0,
cg                         the focus is at x = 0, y = -0.25 * QY / QXX,
cg                         the distance from the vertex to the focus is
cg                         P = 0.25 * abs (QY / QXX), and
cg                         the length of the latus rectum (width at focus) is
cg                         abs (QY / QXX) = 4 * P.
cg
cg                         The standard equation for the parabola or parabolic
cg                         cylinder is
cg                         y = -x^2 / (4 * P), QY > 0, or
cg                         y =  x^2 / (4 * P), QY < 0.

cg    cylinders          A family of circular cylinders may be created with
cg                         command "cylinder", options "concentric", "move",
cg                         "rotate" or "scale" (with restrictions) or as
cg                         follows:
cg
cg                         p pinv (options)
cg
cg                           Create an invariant point, if needed.
cg
cg                         cyl CYL(1) (options)
cg
cg                           Create a base cylinder.
cg
cg                         op opr (options)
cg
cg                           Create a tensor operator, to reflect, rotate,
cg                           invert or scale, if needed.
cg
cg                         v vmove (options)
cg
cg                           Create a vector for use as a translation operator,
cg                           if needed.
cg
cg                         cp CYL(1) CYL(2)
cg
cg                           Copy cylinder CYL(1) to the first cylinder.
cg
cg                         Repeat the following block of commands as many times
cg                         as needed to create the rest of the cylinders.
cg                         See "shortcuts".
cg
cg                         mv cyl CYL(1) vmove
cg
cg                           Move the base cylinder by amount vmove, if needed.
cg
cg                         [invert,reflect,rotate,scale] cyl CYL(1) opr [pinv]
cg
cg                           Invert, reflect, rotate or scale the base cylinder
cg                           with tensor operator opr, if needed.
cg
cg                         cp cyl CYL(1) +
cg
cg                           Copy the base cylinder to the next cylinder.

cc    cylindrical        An option in command "coordinate", to use a 3-D
cc                         coordinate system with the radial, azimuthal and
cc                         axial coordinates (rcyl, theta, z).
cc                         Synonyms:  [cylindrical, cyl].

cg    cylindrical        To create volume elements bounded by surfaces of a
cg                         cylindrical coordinate system, use command "brick".
cg                         To create zones partially or completely bounded by
cg                         concentric cylindrical surfaces, use command
cg                         "cylinder", options "concentric", "scale", and
cg                         command "zone".
cg
cg                         To create arrays of points on surfaces of a
cg                         cylindrical coordinate system, see command
cg                         "point PMESH brick BRNAME mesh block [volume]".
cg
cg                         To find the volume of revolution of a polygonal area
cg                         rotated around an axis, use command "volume".

cc    CYLNAME            The name of a circular cylinder.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.  May not be the same as any other quadric
cc                         surface name QNAME.  Also referred to as CYLNAME1,
cc                         CYLNAME2, ..., CYL(1), CYL(2), ...
cc                         No cylinder name may be "+", "-", "all", "h", "help",
cc                         "list" or "thru", begin with "!" or contain ";".
cc                         Specified with command "cylinder".
cc
cc                         Circular cylinders may appear in commands:
cc                         accelerate, axisym, copy, cylinder, delete,
cc                         distance, invert, move, operator, point, proximal,
cc                         quadric, reflect, rename, rotate, scale, side, track,
cc                         vector.
cc                         Also see commands:  last, list, repack, search, sort.

cc    C____              A synonym for c____ in a comment line.

cc    c____              A synonym for c.

D-------------------------------------------------------------------------------

cc    D                  In command "delimiter", a character to be used as a
cc                         field delimiter, which must be one of the following:
cc                         (blank) (  )  ,  :  <  >  [  \  ]  ^  _  `  {  |  }

cc    D                  In command "solve", the vector of the constants on
cc                         the right-hand side of the three equations.

cc    DANGLE             In command "plane" with option "rotate",
cc                         the angular increment (counterclockwise, with the
cc                         axis pointed at the observer) around the axis vector
cc                         VAXIS, between the normal vectors of successive
cc                         planes.
cc                         May be integer, floating point or a variable.
cc                         Specified in the current angle units.
cc                         See "ANGLE", "angles".

cc    data               An optionin command "variable", to specify more than
cc                         one variable, with values specified in tabular form.
cc                         See "enddata".

cg    data               Each time a geometric or operational object is
cg                         specified or used, its name and some associated data
cg                         is displayed.  For some objects, more data is
cg                         displayed when the object is specified or when it
cg                         is listed by itself.  All data is labeled in a way
cg                         intended to be self-explanatory or to make it
cg                         possible to find a description in geom_base.

cg    data               See "data types", "output data".

cg    data types         Data entered into or displayed by GEOM can be any of
cg                         three types - character, integer or real:
cg
cg                         character - a delimited character string consisting
cg                                     of any of the allowed ASCII keyboard
cg                                     characters.  See "character set".
cg                                     All command names and command arguments
cg                                     shown in lower case are of type
cg                                     character.
cg
cg                         integer   - a delimited character string specifying a
cg                                     positive or negative whole number, in
cg                                     binary, octal, decimal or hexadecimal
cg                                     integer format.  See "integer".
cg                                     Any command argument shown in upper case
cg                                     which allows a numerical value may be of
cg                                     type integer.
cg
cg                         real      - a delimited character string specifying a
cg                                     positive or negative number, in decimal
cg                                     or hexadecimal floating point format.
cg                                     See "floating point".
cg                                     Any command argument shown in upper case
cg                                     which allows a non-integer numerical
cg                                     value may be of type real.

cc    DATAGRP            In command "debug", a data group for which GEOM
cc                         internal parameters and variables will be displayed.
cc                         Also referred to as DATAGRP1, DATAGRP2, ...
cc                         Defined in file geom_internal.  May be any of the
cc                         following:  angles, alias, arithmetic, bin, brick,
cc                         cluster, coordinates, disk, i/o, line, marker, mesh,
cc                         operator, parameter, parse, pdf, plot, point
cc                         polygon, polyhedron, proximal, quadric, symbol,
cc                         synonym, temp, tetrahedron, triangle, variable,
cc                         vector, zone.
cc                         Synonyms:  [alias, al, a], [angles, angle, ang],
cc                         [arithmetic, arith], [brick, br], [cluster, cl],
cc                         [coordinate, coord, cs, system, sys],
cc                         [disk, disc, dk], [environment, env, setup],
cc                         [help, h], [line, l, ln], [marker, mark, m],
cc                         [operator, oper, op], [parameter, param],
cc                         [point, pnt, pt, p], [polygon, polyg, pg],
cc                         [polyhedron, polyh, ph], [proximal, prox],
cc                         [quadric, quad, q], [symbol, sym, symb],
cc                         [synonym, syn], [tetrahedron, tetra, tet],
cc                         [triangle, tri], [variable, var, set, s],
cc                         [vector, vec, v], [zone, zn, z].

cg    date               Dates that may be displayed include the date the code
cg                         was made, and the date of the current run.
cg                         See command "when".
cg                         NOT CURRENTLY AVAILABLE ON THE OPEN YANA CLUSTER.

cg    dbl                See "dbl max", "dbl min".

cg    dbl max            In output from commands "root" and "roots", indicates
cg                         a root of order 2 of a polynomial equation, at a
cg                         maximum of the equation.

cg    dbl min            In output from commands "root" and "roots", indicates
cg                         a root of order 2 of a polynomial equation, at a
cg                         minimum of the equation.

cc    debug              Command to display the values of GEOM internal
cc                         parameters and variables defined in file store.h.
cc                         Most GEOM subroutines contain the command
cc                         "include 'store.h'".  These parameters and variables
cc                         are also listed and defined in file geom_internal,
cc                         in the same directory as the GEOM subroutines.
cc
cc                         Forms include:
cc
ccin                       help debug
ccin                       define [debug]
cc
cc                           Display the command options.
cc
ccin                       debug VARINT1 [VARINT2 ...]
cc
cc                           Display the current values of the GEOM internal
cc                           variables VARINT1 [, VARINT2, ...], which are
cc                           defined in file store.h, in the appropriate format
cc                           for their data type.  Do not use subscripts.
cc                           All values of arrays will be displayed.
cc
cc
ccin                       debug DATAGRP1 [DATAGRP2 ...]
cc
cc                           Display the current values of the GEOM internal
cc                           variables defined in file store.h, for data
cc                           group[s] DATAGRP1 [, DATAGRP2, ...], where DATAGRPn
cc                           may be any of the following:
cc                           angles, alias, arithmetic, big, bin, brick,
cc                           cluster, coordinates, disk, i/o, line, marker,
cc                           mesh, operator, parameter, parse, pdf, plot, point,
cc                           polygon, polyhedron, proximal, quadric, subscript,
cc                           symbol, synonym, temp, tetrahedron, triangle,
cc                           variable, vector, zone.
cc
cc                         Synonyms:  [alias, al, a], [angles, angle, ang],
cc                         [arithmetic, arith], [brick, br], [cluster, cl],
cc                         [coordinate, coord, cs, system, sys],
cc                         [disk, disc, dk], [environment, env, setup],
cc                         [help, h], [line, l, ln], [marker, mark, m],
cc                         [operator, oper, op], [parameter, param],
cc                         [point, pnt, pt, p], [polygon, polyg, pg],
cc                         [polyhedron, polyh, ph], [proximal, prox],
cc                         [quadric, quad, q], [symbol, sym, symb],
cc                         [synonym, syn], [tetrahedron, tetra, tet],
cc                         [triangle, tri], [variable, var, set, s],
cc                         [vector, vec, v], [zone, zn, z].

cc    dec                An option in command "icalc", to set the input mode for
cc                         integers in command "icalc" to decimal.

cg    decay              See "decay constant", "decay time".

cg    decay constant     In an exponential probability bin, the decay constant
cg                         is SIGMA in the relative differential probability
cg                         function exp (-SIGMA * v), where v is the random
cg                         variable, which ranges from VRANL to VRANR,
cg                         as specified in command "bin".  Note the minus
cg                         sign preceding SIGMA.

cg    decay time         To randomly sample decay times for an event with a
cg                         specified half-life T:
cg
cg                         bin BINAME 1 0 VRANR exp SIGMA
cg
cg                           Create a probability bin BINAME with an
cg                           exponentially decaying probability with decay
cg                           constant SIGMA = ln(2)/T, and VRANR = 100*T (which
cg                           has negligible probability).
cg
cg                         pdf PDFNAME = BINAME
cg
cg                           Create a probability distribution function (pdf)
cg                           PDFNAME, consisting only of the probability bin
cg                           BINAME.
cg
cg                         sample PDFNAME [NSAMP|1]
cg
cg                           Sample from pdf PDFNAME NSAMP times.

cg    decimal            The decimal form of an integer M, specified in the
cg                         current integer mode (see command "icalc"),
cg                         may be displayed with command:
cg
cg                         icalc M
cg
cg                           Display M in decimal, hexadecimal, octal and
cg                           (optionally) in binary mode.

cg    decrement          See "decrement names".

cg    decrement names    See "increment names", command "increment".

cg    decryption         Decryption is the process of making encrypted data or
cg                         text readable, using special knowlege intended to
cg                         be available only to certain recipients.
cg                         See command "big".

cc    def                A synonym for define.

cg    default            See "default arguments", "default values".

cc    default arguments
cc                       In commands, optional arguments are shown as follows:
cc
cc                         [argument]
cc
cc                           The literal argument is optional, and there is no
cc                           default value, unless specified in the description
cc                           of the command.
cc
cc                         [ARGUMENT|VALUE]
cc
cc                           The value of ARGUMENT is optional.  If omitted, the
cc                           argument defaults to VALUE.
cc
cc                         [OBJNAME,all]
cc
cc                           The object name OBJNAME or the literal "all" must
cc                           be specified.  No default is allowed.
cc
cc                         [arg1,arg2,arg3|arg1]
cc
cc                           The literal arguments arg1, arg2 or arg3 are
cc                           optional.  If omitted, the argument defaults to
cc                           arg1.
cc
cc                         arg1 [arg2|<]
cc
cc                           If arg2 is not specified, it defaults to arg1.
cc
cc                         Other defaults may be defined in the descriptions of
cc                         the commands.

cg    default values     A number of objects are assigned default values at the
cg                         beginning of each GEOM run.
cg
cg                         The input medium is the user's terminal
cg                           (do NOT use "<" or ">" on the GEOM execution line).
cg                           Change with command "input" or "return".
cg                           See "redirect input".
cg                         The output medium (in addition to the standard
cg                           output, normally to the user's terminal) is
cg                           file geom_hsp.  Change with command "output".
cg                           See "redirect output".
cg                         The field delimiter is a blank character.
cg                           Change with command "delimiter".
cg                         The numerical tolerance limit TOL = 10^(-11).
cg                           Change with command "tol".
cg                         The coordinate system is Cartesian (x, y, z).
cg                           Change with command "coordinate".
cg                         The unit for input and display of angles is degrees.
cg                           Change with command "angles".
cg                         The mode for integer input in command "icalc" is
cg                           decimal.  Change with command "icalc".
cg                         The mode for integer display in command "icalc" is
cg                           octal, decimal and hexadecimal.
cg                           Turn an added binary display on and off with
cg                           commands "icalc binary" and "icalc nobin".
cg
cg                         symbol pi      = 3.141592653589793
cg                         symbol deg/rad = 57.29577951308232
cg                         symbol rad/deg = 0.01745329251994330
cg                         symbol ebase   = 2.718281828459045
cg                         symbol rgold   = 1.618033988749894
cg                         symbol euler   = 0.577215664901533861
cg
cg                         Change or reinstate any of the five preceding
cg                         symbols with command "symbol".

cg    define             See "create", commands "define", "alias", "marker".

cc    define             Command to display an entry in file geom_base, which is
cc                         assumed to be in one of the locations:
cc                         geom_base                          (local)
cc                         ~edwards/work/geom/doc/geom_base   (YANA Cluster)
cc                         A list of all such entries is in file geom_define.
cc
cc                         Note:  no replacement of symbols will be done
cc                         in this command.
cc
cc                         See "character set" for the ASCII characters which
cc                         may be used in command "define".
cc
cc                         Forms include:
cc
ccin                       help define
ccin                       define [help]
cc
cc                           Display the command options.
cc
ccin                       define 'ENTRY'
cc
cc                           Display entry ENTRY of geom_base.  Case is ignored.
cc                           The first 19 characters of ENTRY must match columns
cc                           7-25 of the first line of entries in this file,
cc                           ignoring any trailing blanks.
cc                           If ENTRY is bracketed by single quotes, repeat any
cc                           internal single quote.  If ENTRY is bracketed by
cc                           double quotes, repeat any internal double quote.
cc
cc                         define 'X'
cc
cc                           Display the first line of all entries in geom.base
cc                           that begin with the letter "X".  Case is ignored.
cc
cc                         Synonyms:  [", ' (in pairs)], [define, def],
cc                         [help, h].
cc
cc                         See "help", "definition", "geom_define".

cg    definition         You can store and display your own comment, description
cg                         or definition of any object or word you desire,
cg                         OBJNAME, with command "alias", as follows:
cg
cg                         alias OBJNAME = "# DEFINITION"
cg
cg                           Assign alias OBJNAME to the comment line
cg                           "# DEFINITION", where DEFINITION is any character
cg                           string that will fit on the input line, describing
cg                           the object named OBJNAME.  OBJNAME should not be
cg                           the same as the first word of any command that you
cg                           might want to use.
cg
cg                         OBJNAME
cg
cg                           Display the character string for which OBJNAME is
cg                           the alias.
cg
cg                         Example:
cg
cg                         You type:
cg                         alias vnorm = "# The vector normal to plane plx."
cg
cg                         Any time later, you type:
cg                         vnorm
cg                         The code then displays:
cg                         # The vector normal to plane plx.
cg
cg                         You can store and display your own comment,
cg                         description or definition, to go with any single
cg                         character AMNAME you desire, with command "marker",
cg                         as follows:
cg
cg                         marker AMNAME = "TEXT"
cg
cg                           Assign to the 1-character marker AMNAME the text
cg                           "TEXT", where TEXT is any character string that
cg                           will fit on the input line.
cg
cg                         marker AMNAME
cg
cg                           Display the TEXT assigned to marker AMNAME.
cg
cg                         Example:
cg
cg                         You type:
cg                         marker a = "Note:  coordinates are in millimeters."
cg
cg                         Any time later, you type:
cg                         marker a
cg                         The code then displays:
cg                         mark a  Note:  coordinates are in millimeters.

cc    deg                A synonym for degrees in command "angles".

cn    deg.mac            A macro file for converting from degrees, minutes and
cn                         seconds to decimal degrees.  Type "in deg.mac ?" for
cn                         info.  In ~/work/geom/test .  See "dms.mac".

cc    deg/rad            An option in command "symbol", argument SYMBNAME,
cc                         to create symbol deg/rad with value
cc                         57.29577951308232087679815481410517033240547246658
cc                         Store as a big integer with command "input big.mac",
cc                         with file big.mac in the same directory as GEOM.

cg    deg/rad            Symbol, degrees per radian.  Generated as a
cg                         symbol at the beginning of the run.
cg                         deg/rad = 180.0 / pi.
cg                         deg/rad = 57.29577951308232 degrees per radian.
cg                         rad/deg = 0.01745329251994330 radians per degree.
cg                         pi      = 3.141592653589793... = acos (-1).
cg
cg                         symbol SYMBNAME deg/rad
cg
cg                           Set symbol SYMBNAME to
cg                           180 / pi = 57.29577951308232.
cg
cg                         symbol SYMBNAME rad/deg
cg
cg                           Set symbol SYMBNAME to
cg                           pi / 180 = 0.01745329251994330.

cg    degenerate         A quadric surface may be degenerate:
cg
cg                           F(x,y,z) =    QC          +
cg                           QX  * x     + QY  * y     + QZ  * z     +
cg                           QXY * x * y + QYZ * y * z + QZX * z * x +
cg                           QXX * x^2  + QYY * y^2  + QZZ * z^2  = 0
cg
cg                         Degenerate quadric surfaces (in standard form,
cg                         all coefficients positive):
cg
cg                         Imaginary intersecting planes:
cg                           (a straight line)              x^2 + QYY*y^2 = 0
cg                         Imaginary elliptic cone:
cg                           (a point)            x^2 + QYY*y^2 + QZZ*z^2 = 0
cg                         Imaginary circular cone:
cg                           (a point)                x^2 + y^2 + QZZ*z^2 = 0
cg
cg                         See "quadric surfaces".

cc    degree             A synonym for degrees in command "angles".

cc    DEGREES            In command "angles", the integer number of degrees of
cc                         an angle specified in degree, minutes and second
cc                         units.
cc                         May be integer, floating point or a variable.
cc                         The absolute value of DEGREES + MINUTES / 60
cc                         + SECONDS / 3600 must not exceed the largest machine
cc                         integer.

cc    degrees            An option in command "angles", to specify that angles
cc                         are to be input and displayed in degrees.

cg    degrees            A unit of measurement of angles.  A full circle has
cg                         360 degrees or 2 * pi radians.
cg                         One radian = 180/pi (~57.29577951308232) degrees.
cg                         One degree = pi/180 (~0.01745329251994330) radians.

cc    del                A synonym for delete.

cc    delete             An option in command "plot", to delete points from the
cc                         list of plot points.  This does not delete the points
cc                         from the list of geometric points.

cg    delete             See "delete objects", command "delete".

cc    delete             Command to delete aliases, bricks, probability bins,
cc                         big integers, clusters, annular disks, lines,
cc                         markers, tensor operators, planes, points,
cc                         regular polygons, quadric surfaces (including general
cc                         and axisymmetric, circular cones, circular cylinders,
cc                         ellipsoids, hyperbolic paraboloids and spheres),
cc                         regular polyhedrons, probability distribution
cc                         function (pdfs), tetrahedrons, triangles, vectors,
cc                         variables and zones.
cc
cc                         Command "delete" relates to objects:  alias, axisym,
cc                         big, bin, brick, cluster, cone, cylinder, disk,
cc                         ellipsoid, hyperb, line, marker, operator, pdf,
cc                         plane, point, polygon, polyhedron, quadric, sphere,
cc                         symbol, tetrahedron, triangle, variable, vector,
cc                         zone.
cc
cc                         Option "all" must be verified, if input is from the
cc                         user's terminal (do NOT use "<" on the GEOM execution
cc                         line).
cc
cc                         Fix errors with command "undo", "redo" or "indo",
cc                         or by cutting and pasting from the display.
cc
cc                         Note:  no replacement of symbols will be done
cc                         in the commands "delete symbol ...", "delete alias".
cc
cc                         Markers with dependencies (plot title, plot axis
cc                         labels or plot point titles) will not be deleted.
cc                         You must respecify the dependent object first.
cc
cc                         Points with dependencies (line, triangle, regular
cc                         polygon, annular disk, regular polyhedron or a
cc                         tetrahedron) will not be deleted.  You must delete
cc                         or respecify the dependent object first.  A warning
cc                         will be displayed if a deleted point is in a cluster,
cc                         unless it is the cluster that is being deleted.
cc
cc                         A warning will be displayed if a deleted bin is in a
cc                         probability distribution function (pdf), unless it is
cc                         the pdf that is being deleted.
cc
cc                         Do not use "+" or "-" for object names in these
cc                         commands.
cc
cc                         Forms include:
cc
ccin                       help delete
ccin                       delete [help]
cc
cc                           Display the command options.
cc
ccin                       delete OBJTYPE all
cc
cc                           Delete all objects of type OBJTYPE (alias, axisym,
cc                           big, bin, brick, cluster, cone, cylinder, disk,
cc                           ellipsoid, hyperb, line, marker, operator, pdf,
cc                           plane, point, polygon, polyhedron, quadric, sphere,
cc                           symbol, tetrahedron, triangle, variable, vector,
cc                           zone).
cc                           Requires verification by the user, if input is from
cc                           the user's terminal (do NOT use "<" on the GEOM
cc                           execution line).
cc
ccin                       delete OBJTYPE OBJNAME all
cc
cc                           Delete all objects of type OBJTYPE (see above) with
cc                           the names OBJNAME(NSUB1,NSUB2,...), where NSUBi is
cc                           any subscript or null.
cc
ccin                       delete OBJTYPE OBJNAME
cc
cc                           Delete the object of type OBJTYPE (see above) with
cc                           the name OBJNAME.
cc
ccin                       delete OBJTYPE OBJNAME1 thru OBJNAME2
cc
cc                           Delete any objects of type OBJTYPE (see above) with
cc                           names from OBJNAME1 through OBJNAME2.  WARNING:
cc                           the name comparison is with left-adjusted ASCII
cc                           names, except that subscripts are compared as
cc                           integers.
cc
cc                           NOTE!  No object may have the name "thru".
cc
ccin                       delete cluster CLNAME
cc
cc                           Delete cluster CLNAME.  The points in cluster
cc                           CLNAME are not deleted.
cc
ccin                       delete point cluster CLNAME
cc
cc                           Delete the points in cluster CLNAME.  Delete
cc                           cluster CLNAME if all of its points are deleted.
cc
ccin                       delete bin pdf PDFNAME
cc
cc                           Delete the probability bins in pdf PDFNAME.
cc                           Delete pdf PDFNAME if all of its bins are deleted.
cc
cc                         Synonyms:  [alias, al, a,], [brick, br],
cc                         [cluster, cl], [copy, cp, dup, duplicate],
cc                         [cylinder, cyl], [delete, del, remove, rm],
cc                         [disk, disc, dk],
cc                         [ellipsoid, ell, el, ellipse], [help, h],
cc                         [hyperb, saddle], [line, l, ln], [marker, mark, m],
cc                         [operator, oper, op], [plane, pl],
cc                         [point, pnt, pt, p], [polygon, polyg, pg],
cc                         [polyhedron, polyh, ph], [quadric, quad, q],
cc                         [sphere, sph], [symbol, sym, symb],
cc                         [tetrahedron, tetra, tet], [triangle, tri],
cc                         [variable, var, set, s], [vector, vect, v],
cc                         [zone, zn, z].

cc    delete             An option in command "mesh", to delete one or more
cc                         layers of the mesh.
cc                         Synonyms:  [delete, del, remove, rm].

cg    delete objects     See command "delete".

cc    delim              A synonym for delimiter.

cc    delimit            A synonym for delimiter.

cg    delimited          A delimited argument or character string is delimited
cg                         on the left by the beginning of the line or the
cg                         field delimiter, and on the right by the field
cg                         delimiter or the end of the line (up to 80
cg                         characters).

cg    delimiter          The field delimiter (FD) is the single character used
cg                         to delimit fields (arguments) in the input lines.
cg
cg                         The FD is initially a blank character, but may be
cg                         changed with command "delimiter", to one of the
cg                         following characters:
cg                         ,  :  <  >  [  \  ]  ^  _  `  {  |  }
cg                         Do not use a character as a delimiter in a command
cg                         that requires the same character as input.
cg
cg                         All commands shown in this file, and in the help
cg                         messages displayed by GEOM, are shown with a blank
cg                         character as the FD.  If the FD is not a blank
cg                         character, replace all blank characters or sequential
cg                         strings of blank characters shown in the examples
cg                         with the actual FD (except in the quoted strings of
cg                         commands "alias", "marker" and "define").
cg
cg                         If the FD is a blank character, any number of
cg                         adjacent blank characters may be used instead of a
cg                         single blank character, and blank characters used
cg                         before the first non-blank character and after the
cg                         last non-blank character will be ignored.
cg
cg                         If the FD is a blank character, do not include any
cg                         blank characters in any delimited argument or
cg                         character string, except in the quoted strings of
cg                         commands "alias", 'define" and "marker", or in the
cg                         variable tag specified in command "variable", option
cg                         "tag".
cg
cg                         If the FD is not a blank character, do not use it to
cg                         begin an input line, or an extra null field will be
cg                         produced.  Trailing null fields at the end of an
cg                         input line will be ignored, but any other null field
cg                         is an error.
cg
cg                         Sign prefixes on variable names do not use a field
cg                         delimiter.  See "sign".

cc    delimiter          Command to display or specify the field delimiter used
cc                         to delimit input line arguments.  The field delimiter
cc                         must be a blank character or one of the following
cc                         characters:
cc                         ,  :  <  >  [  \  ]  ^  _  `  {  |  }
cc
cc                         Forms include:
cc
ccin                       help delimiter
ccin                       delimiter help
cc
cc                           Display the command options, when the field
cc                           delimiter is a blank character.
cc
ccin                       helpCdelimiter
ccin                       delimiterChelp
cc
cc                           Display the command options, when the field
cc                           delimiter is any allowed character "C".
cc
ccin                       delimiter
cc
cc                           Change the field delimiter to a blank character,
cc                           when it is initially any character.
cc
ccin                       delimiter D
cc
cc                           Change the field delimiter to any allowed character
cc                           "D", when it is initially a blank character.
cc
ccin                       delimiterCD
cc
cc                           Change the field delimiter to any allowed character
cc                           "D", when it is initially the character "C".
cc
cc                         Synonyms:  [delimiter, delim, delimit], [help, h].

cg    dependent          Some geometric objects are dependent on points:
cg                         lines, triangles, regular polygons, annular disks,
cg                         regular polyhedrons, and tetrahedrons.  A change in
cg                         the coordinates of a point will change the geometry
cg                         of the dependent object.  A change in the name of a
cg                         point will have no effect on the dependent object,
cg                         except to change the name of the point in its
cg                         specification.  A point with dependent objects may
cg                         not be deleted.

cg    derivatives        When using command "roots" to find the real and/or
cg                         complex roots of a polynomial equation in z:
cg                         P(z) = a0 + a1*z + a2*z^2 + a3*z^3 + a4*z^4 = 0,
cg                         the real values of z and P(z) are displayed for which
cg                         each of the derivatives of P(z) are zero, up to the
cg                         highest derivative which is still a function of z.
cg                         These include the maximum and minimum points, where
cg                         the first derivative is zero:
cg                           P'(z) = a1 + 2*a2*z + 3*a3*z^2 + 4*a4*z^3 = 0,
cg                         the inflection points, where the second derivative
cg                         is zero:
cg                           P''(z) = 2*a2 + 6*a3*z + 12*a4*z^2 = 0,
cg                         and the point where the third derivative is zero:
cg                           P'''(z) = 6*a3 + 24*a4*z = 0.
cg
cg                         To search for real roots, extrema and inflection
cg                         points of a polynomial equation using Newtonian
cg                         iteration, use command "root".
cg
cg                         See "spatial derivatives".

cg    destroy            To destroy an object, use command "delete".

cg    det                An invariant of a quadric surface, for translations and
cg                         rotations.  See "invariants of quadric".

cg    determinant        The determinant of a tensor operator is displayed
cg                         whenever the tensor operator is displayed.
cg                         The determinant for a rotation operator is 1.
cg                         The determinant for an inversion operator is -1.
cg                         The determinant for a reflection operator is -1.
cg                         The determinant for a scaling operator is the
cg                         first, second or third power of the scale factor,
cg                         for linear, radial or 3-D (options "scale" or
cg                         uniform") scaling.

cg    determinant        To find the value of a 3 by 3 determinant:
cg
cg                         variable VARNAME triple VNAME1 VNAME2 VNAME3
cg
cg                           Create variable VARNAME with the value of the 3 by
cg                           3 determinant for which the three row or column
cg                           vectors are the vectors VNAME1, VNAME2 and VNAME3.

cc    DEV                In command "bin", the standard deviation.

cg    deviation          See "expected value".

cg    diatonic           See "diatonic scale".

cg    diatonic scale     In music, a diatonic scale in a major key consists
cg                         of eight tones, with intervals from the initial (key)
cg                         tone of two whole tones, a semitone, three whole
cg                         tones, and a semitone, ending on the octave of the
cg                         first tone.  For example, on a piano, the diatonic
cg                         scale for C major is entirely on the white keys,
cg                         consisting of C-D-E-F-G-A-B-C.  The diatonic scale
cg                         for a minor key, e.g. A minor, A-B-C-D-E-F-G-A, has
cg                         semitones for the second and fifth intervals.
cg
cg                         See "equally-tempered".

cn    dice.mac           A macro file for rolling two dice, to demonstrate the
cn                         use of bins and pdfs.  In ~/work/geom/test .

cg    digits             See "significant figures".

cg    dihedral           See "angle, dihedral".

cg    direction          Reverse the direction of a vector V1 with command
cg                         "vector V1 rel -1"

cg    direction          See "direction cosine", "direction vector".

cg    direction cosine   A direction cosine is a component of a unit direction
cg                         vector in the direction of one of the axes of the
cg                         coordinate system.

cg    direction vector   The direction vector of a moving object is the vector
cg                         in the direction of motion.  A unit vector parallel
cg                         to the direction vector has components in the
cg                         directions of the axes of the coordinate system.
cg                         These components are called direction cosines.
cg                         In linear motion, the direction cosines are constant
cs                         in a Cartesian (xyz) coordinate system, but change
cg                         continuously in a cylindrical or spherical coordinate
cg                         system.  See "coordinate conversion",
cg                         "vector conversion".

cg    directories        See "geom_summ", "geom_files".

cg    disallowed         See "disallowed names".

cg    disallowed names   Some names are disallowed for all or some object names,
cg                         because they make interpretation of a command
cg                         ambiguous.
cg                         No name may be "+", "-", "all", "h", "help",
cg                         "list" or "thru", begin with "!" or contain ";".
cg                         A point name must not be "cluster" or a synonym.
cg                         A cluster name must not be "point" or a synonym.
cg                         A quadric surface name must not be "types".

cc    disc               A synonym for disk.

cg    discrete           See "discrete event", "discrete object",
cg                         "discrete value".

cg    discrete event     A type of probability bin, which assigns a relative
cg                         total probability to a discrete event or object.
cg                         The discrete object may be any of the objects used
cg                         in GEOM, including a probability distribution
cg                         function (pdf).
cg                         See "discrete value", "uniform", "linear",
cg                         "power-law", "exponential".
cg                         See commands "bin", "pdf", "sample".

cg    discrete object    A type of probability bin, which assigns a relative
cg                         total probability to a discrete event or object.
cg                         The discrete object may be any of the objects used
cg                         in GEOM, including a probability distribution
cg                         function (pdf).
cg                         See "discrete value", "uniform", "linear",
cg                         "power-law", "exponential".
cg                         See commands "bin", "pdf", "sample".

cg    discrete value     A type of probability bin, which assigns a relative
cg                         total probability to a discrete value of a random
cg                         variable.
cg                         See "discrete event", "uniform", "linear",
cg                         "power-law", "exponential".
cg                         See commands "bin", "pdf", "sample".

cg    disk               An annular disk is a surface in 3-D space, lying in a
cg                         plane, and bounded by two circles having a common
cg                         center in the same plane.  For a simple disk, the
cg                         radius of the inner circle is zero.  The disk is
cg                         dependent on the point used to specify the center of
cg                         the circles, which may be changed.  An annular disk
cg                         may be used to create a plane, with command "plane".
cg                         The maximum number of disks is now 1000.
cg
cg                         The following commands relate to annular
cg                         disks:
cg                         copy, debug, delete, disk, help, last, list, plane,
cg                         point, rename, repack, search, sort, symbol, synonym,
cg                         tables.

cc    disk               An option in command "debug", to display GEOM internal
cc                         parameters and variables for annular disks:
cc                         ndiskm, ndisks, adisk, radkin, radkout, acendk,
cc                         xnormdk, ynormdk, znormdk, adisks, ladisks.
cc                         Synonyms:  [disk, disc, dk].

cc    disk               Command to display or create circular or annular
cc                         disks.  A disk may be replaced.  The display for a
cc                         disk includes the central point, the normal vector,
cc                         the inner and outer radii, the inner and outer
cc                         circumferences, and the areas of the central hole and
cc                         the annulus.
cc                         See command "circle" to find the circle through
cc                         three specified points.
cc                         See "do loop use".
cc
cc                         Command "disk" relates to objects:  disk, point,
cc                         variable, vector.
cc
cc                         Forms include:
cc
ccin                       help disk
ccin                       disk [help]
cc
cc                           Display the command options.
cc
ccin                       disk [all,list]
cc
cc                           Display all annular disks.
cc
ccin                       disk list DKNAME1 DKNAME2 DKNAME3 ...
cc
cc                           Display annular disks DKNAME1, DKNAME2, DKNAME3,
cc                           ..., with or without subscripts.
cc
ccin                       disk DKNAME
cc
cc                           Display annular disk DKNAME.
cc
ccin                       disk DKNAME fit PCEN VNORM RADKIN RADKOUT
cc
cc                           Create annular disk DKNAME, centered at point PCEN,
cc                           with normal vector VNORM, with inner radius RADKIN,
cc                           outer radius RADKOUT.  Any later change in the
cc                           coordinates or name of point PCEN will change the
cc                           definition of annular disk DKNAME.  Use "+" or "-"
cc                           instead of DKNAME to form the name by incrementing
cc                           or decrementing the base name for annular disks.
cc                           See command "last", "increment names".
cc
cc                         Synonyms:  [disk, disc, dk], [help, h].

cc    disk               An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on one or more annular disks.
cc                         Synonyms:  [disk, disc, dk].

cg    disk arrays        Disks may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    displace           See "move".

cg    displacement       A displacement is the difference between the final and
cg                         initial position of an object.

cc    display            A synonym for list in command "list".

cg    display            The code displays data on the user's terminal
cg                         screen and in the output file (geom_hsp, or the
cg                         file(s) specified by the user with command "output"),
cg                         or specified on the GEOM execution line.
cg                         See "display objects", "redirect output", command
cg                         "list".

cg    display            See "display objects", command "list".

cg    display objects    The commands for displaying objects have the general
cg                         forms:
cg
cg                         OBJTYPE [all,list]
cg
cg                           Display all objects of type OBJTYPE.
cg                           Use the longest display.
cg
cg                         OBJTYPE OBJNAME
cg
cg                           Display object type OBJTYPE with name OBJNAME.
cg                           Use the longest display.
cg
cg                         OBJTYPE list OBJNAME1 OBJNAME2 OBJNAME3 ...
cg
cg                           Display objects of type OBJTYPE with names OBJNAME,
cg                           OBJNAME2, OBJNAME3, ..., with or without
cg                           subscripts.  Use the shortest display, unless there
cg                           is only one such object.
cg
cg                         list [OBJTYPE,all]
cg
cg                           Display only the names of all objects of [type
cg                           OBJTYPE, or all types].
cg                           Synonyms:  [list, display, print].
cg
cg                         last [OBJTYPE,all]
cg
cg                           Display only the names of the last object specified
cg                           of [type OBJTYPE, or all types].
cg
cg                         sort [OBJTYPE,all] [+,-,?|+]
cg
cg                           Display only the names of all objects of [type
cg                           OBJTYPE, or all types], after sorting the objects
cg                           into [increasing, decreasing, random] ASCII order,
cg                           with increasing order the default option.
cg
cg                         search OBJNAME1 OBJNAME2 OBJNAME3 ...
cg
cg                           Display all objects with object names the same as
cg                           OBJNAME1, OBJNAME2, OBJNAME3, ...  or if any of the
cg                           latter are a single character, with object names
cg
cg                           Display all marker texts, symbol and alias
cg                           replacements the same as OBJNAME1, OBJNAME2,
cg                           OBJNAME3, ...  or if any of the latter are a single
cg                           character, beginning with that character.
cg
cg                           Display all variables with numerical values equal
cg                           to OBJNAME1, OBJNAME2, OBJNAME3, ...
cg
cg                         search all
cg
cg                           Display all objects with object names.
cg
cg                         See "OBJTYPE", "OBJNAME", "create objects".

cg    dist               A synonym for distance in command "distance".

cg    dist               See "dist to collision".

cg    distal             The opposite of proximal.  The most distant.
cg                         See "distal point".

cg    distal point       For an external point P1, the distal point P2 (farthest
cg                         from point P1) on a quadric surface F(x,y,z) = 0,
cg                         with normal vector N = grad F = (NX, NY, NX),
cg                         satisfies the same equations as a proximal point:
cg
cg                         (X2 - X1) / NX =
cg                         (Y2 - Y1) / NY =
cg                         (Z2 - Z1) / NZ =
cg                         (P2 - P1) dot N / N^2 = distance / |N|.
cg
cg                         In general, this leads to a sixth order equation,
cg                         requiring iterative numerical methods of solution.
cg                         See commands "distance", "proximal", "side".

cg    distance           The straight-line distance between two points in 3-D
cg                         space, or the perpendicular distance from a point to
cg                         a line, plane or surface, or the perpendicular
cg                         distance between two parallel lines or planes.
cg                         See commands "accelerate", "distance", "proximal",
cg                         "side", "track".
cg
cg                         To find the distance between two points, use any of
cg                         the methods:
cg
cg                         distance point PNAME1 point PNAME2
cg
cg                           Display the distance between points PNAME1 and
cg                           PNAME2.
cg
cg                         line ALNAME = PNAME1 PNAME2
cg
cg                           Create line ALNAME1 from point PNAME1 to point
cg                           PNAME2, and display its direction and length.
cg
cg                         vector VNAME = PNAME1 PNAME2
cg
cg                           Create vector VNAME, directed from point PNAME1
cg                           toward point PNAME2, with length equal to the
cg                           distance from PNAME1 to PNAME2, and bound at
cg                           PNAME1, and display its direction and length.
cg
cg                         To find the distance between the two parallel planes
cg                         of a quadric surface of that form:
cg
cg                         quadric QNAME
cg
cg                           Display the coefficients of quadric surface QNAME
cg                           (before and after a principal axis transformation),
cg                           the intercepts on the axis, and the distance
cg                           between the parallel planes.
cg
cg                         To find the minimum distance between a point and a
cg                         quadric surface, use command "distance", "proximal"
cg                         or "side".
cg
cg                         To find the distances from a point to the six
cg                         surfaces bounding a brick, and to find if the point
cg                         is in the brick, use command "distance".
cg                         Also see command "where".
cg
cg                         To find the distances from a point to the four planes
cg                         bounding a tetrahedron, and to find if the point is
cg                         in the tetrahedron, use command "distance".
cg                         Also see command "where".
cg
cg                         To find the distances from a point to the quadric
cg                         surfaces bounding a zone, and to see if the point is
cg                         in the zone, use command "distance".
cg                         Also see command "where".
cg
cg                         To find the approximate distance or the intersection
cg                         between a line and a quadric surface, use command
cg                         "track".
cg
cg                         To find the distance between two circles in a major
cg                         plane, use command "intcirc".
cg
cg                         To find the distance and proximal points and/or
cg                         intersection of any combination of planes, spheres
cg                         and circular cylinders, use command "distance".
cg
cg                         To find the distance from a plane to any quadric
cg                         surface, use command "distance".
cg
cg                         To find the distance between a sphere and a quadric
cg                         surface, first find the distance from the point at
cg                         the center of the sphere to the quadric surface,
cg                         with command "distance", "proximal" or "side", then
cg                         subtract the radius of the sphere.  A negative result
cg                         indicates overlap.
cg
cg                         To find the distance between any two quadric
cg                         surfaces, use command "distance".
cg
cg                         To find the distance between a point and a toroid
cg                         generated by a quadric curve, see "toroid".

cc    distance           Command to find the distance between two geometric
cc                         objects, which may be points, lines, triangles or
cc                         planes, a point or plane and a quadric surface, or
cc                         a point and a brick, tetrahedron or zone, any
cc                         combination of spheres and circular cylinders, or
cc                         any two quadric surfaces.
cc                         When possible, find any symmetries, points of
cc                         intersection or tangency or curves of intersection.
cc                         In the case of clusters of points, also find the
cc                         points with the minimum and maximum distances.
cc                         In the case of two quadric surfaces, specify planes
cc                         before spheres before other quadric surfaces.
cc                         Also, see "toroid".
cc
cc                         Command "distance" relates to objects:  axisym,
cc                         brick, cluster, cone, cylinder, ellipsoid, hyperb,
cc                         line, plane, point, quadric, sphere, symbol,
cc                         tetrahedron, triangle, zone.
cc
cc                         The minimum distance found may be stored in variable
cc                         VARNAME with command:
cc                         variable VARNAME distance
cc
cc                         The proximal point found on the second object may be
cc                         stored in point PNAME with command
cc                         "point PNAME proximal".
cc
cc                         The vector between the proximal points may be stored
cc                         in vector VNAME with command
cc                         "vector VNAME proximal".
cc
cc                         Also see commands "accelerate", "intcirc",
cc                         "proximal", "side", "track", "variable".
cc
cc                         Forms include:
cc
ccin                       help distance
ccin                       distance [help]
cc
cc                           Display the command options.
cc
ccin                       distance point PNAME1 point PNAME2
cc
cc                           Find the distance from point PNAME1 to point
cc                           PNAME2.  Another way is to create a line from point
cc                           PNAME1 to point PNAME2.
cc
ccin                       distance point PNAME cluster CLNAME
cc
cc                           Find the distances from point PNAME1 to the points
cc                           in cluster CLNAME.
cc
ccin                       distance cluster CLNAME1 cluster CLNAME2
cc
cc                           Find the distances from the points in cluster
cc                           CLNAME1 to the points in cluster CLNAME2 (which
cc                           may be CLNAME1).
cc
ccin                       distance point PNAME line ALNAME
cc
cc                           Find the distance from point PNAME to line ALNAME,
cc                           and the nearest point on the line.
cc
ccin                       distance cluster CLNAME line ALNAME
cc
cc                           Find the distances from the points in cluster
cc                           CLNAME to line ALNAME, and the nearest points on
cc                           the line, for each point.
cc
ccin                       distance point PNAME triangle TRNAME
cc
cc                           Find the distance from point PNAME to triangle
cc                           TRNAME, and the nearest point on the triangle.
cc
ccin                       distance cluster CLNAME triangle TRNAME
cc
cc                           Find the distances from the points in cluster PNAME
cc                           to triangle TRNAME, and the nearest point on the
cc                           triangle for each point.
cc
ccin                       distance point PNAME QTYPE QNAME
cc
cc                           Find the distance from point PNAME to the quadric
cc                           surface of type QTYPE (plane, sphere, cylinder,
cc                           cone, hyperb, ellipsoid, axisym, quadric) with name
cc                           QNAME, and the nearest point on the quadric
cc                           surface.  Check with commands "proximal", "side".
cc                           See "toroid" for a method of finding the distance
cc                           from a point to a toroid generated by a quadric
cc                           curve.
cc
ccin                       distance cluster CLNAME QTYPE QNAME
cc
cc                           Find the distances from the points in cluster
cc                           CLNAME to the quadric surface of type QTYPE (plane,
cc                           sphere, cylinder, cone, hyperb, ellipsoid, axisym,
cc                           quadric) with name QNAME, and the nearest point on
cc                           the quadric surface, if possible.
cc                           See the preceding command form.
cc
ccin                       distance point PNAME brick BRNAME
cc
cc                           Find the distances from point PNAME to each of the
cc                           six surfaces bounding brick TETNAME, and find if
cc                           the point is inside the brick.  Also see command
cc                           "where".
cc
ccin                       distance point PNAME tetrahedron TETNAME
cc
cc                           Find the distances from point PNAME to each of the
cc                           four planes bounding tetrahedron TETNAME, and find
cc                           if the point is inside the tetrahedron.  Also see
cc                           command "where".
cc
ccin                       distance point PNAME zone ZNAME
cc
cc                           Find the distances from point PNAME to each of the
cc                           quadric surfaces bounding zone ZNAME, and find if
cc                           the point is inside the zone.  See the preceding
cc                           command forms.  Also see command "where".
cc
ccin                       distance line ALNAME1 line ALNAME2
cc
cc                           Find the distance from line ALNAME1 to line
cc                           ALNAME2, and the nearest points on each line.
cc
ccin                       distance line ALNAME triangle TRNAME
cc
cc                           Find the intersection of line ALNAME and triangle
cc                           TRNAME or find the distance, if they are parallel.
cc
ccin                       distance line ALNAME plane PLNAME
cc
cc                           Find the intersection of line ALNAME and plane
cc                           PLNAME or find the distance, if they are parallel.
cc
ccin                       distance triangle TRNAME1 triangle TRNAME2
cc
cc                           Find the line of intersection of the two triangles
cc                           TRNAME1 and TRNAME2 or find the distance, if they
cc                           are parallel.
cc
ccin                       distance triangle TRNAME plane PLNAME
cc
cc                           Find the line of intersection of triangle TRNAME
cc                           and plane PLNAME or find the distance, if they are
cc                           parallel.
cc
ccin                       distance plane PLNAME1 plane PLNAME2
cc
cc                           Find the distance and/or intersection of the two
cc                           planes PLNAME1 and PLNAME2.  For more information,
cc                           repeat with the second "plane" replaced by
cc                           "quadric".
cc
ccin                       distance plane PLNAME sphere SPHNAME
cc
cc                           Find the distance and/or intersection of plane
cc                           PLNAME and sphere SPHNAME.  See "separation".
cc
ccin                       distance plane PLNAME cylinder CYLNAME
cc
cc                           Find the distance and/or intersection of plane
cc                           PLNAME and circular cylinder CYLNAME.  See
cc                           "separation".  For more information, repeat with
cc                           "cylinder" replaced by "quadric".
cc
ccin                       distance plane PLNAME QTYPE QNAME
cc
cc                           Find the distance and/or intersection of plane
cc                           PLNAME and quadric type QTYPE (axisym, cone,
cc                           cylinder, ellipsoid, hyperb, plane, quadric or
cc                           sphere) with name QNAME.
cc                           See the preceding three commands.
cc                           Also see "quadric", "separation", "projection".
cc
ccin                       distance sphere SPHNAME1 sphere SPHNAME2
cc
cc                           Find the distance and/or intersection of the two
cc                           spheres SPHNAME1 and SPHNAME2.  See "separation".
cc                           If the spheres are concentric, there are an
cc                           infinite number of pairs of proximal points.
cc
ccin                       distance cylinder CYLNAME sphere SPHNAME
cc
cc                           Find the distance and/or intersection of sphere
cc                           SPHNAME and circular cylinder CYLNAME.  See
cc                           "separation".  If the sphere is on the axis of the
cc                           cylinder, there are an infinite number of proximal
cc                           points.
cc
ccin                       distance cylinder CYLNAME1 cylinder CYLNAME2
cc
cc                           Find the distance and/or intersection of the two
cc                           circular cylinders CYLNAME1 and CYLNAME2.  See
cc                           "separation".  If the cylinders are concentric,
cc                           there are an infinite number of pairs of proximal
cc                           points.
cc
ccin                       distance quadric QNAME1 quadric QNAME2
cc
cc                           Find the distance and proximal points, or find a
cc                           randomly sampled point on the intersection curve of
cc                           the two quadric surfaces QNAME1 and QNAME2.  May
cc                           fail if the surfaces are almost flat at their
cc                           proximal points, intersect at very small angles or
cc                           are tangent.
cc
cc                           Note:  the two surfaces QNAME3 and QNAME4 have the
cc                           same intersection curve as QNAME1 and QNAME2:
cc                             quadric QNAME3 sum QNAME1 QNAME2 N2 -N1
cc                             quadric QNAME4 sum QNAME1 QNAME2 N2  N1
cc                           and are orthogonal at point P, if N1 and N2 are the
cc                           magnitudes of the normal vectors of QNAME1 and
cc                           QNAME2 at point P.  See command "arc".
cc
cc                           Note:  either surface QNAME1 or QNAME2 may be
cc                           replaced by surface QNAME3 above, which will
cc                           have a zero value of one of the invariants
cc                           "trace", "dsum" or "det", if N1 and N2 are the
cc                           values of that invariant for QNAME1 and QNAME2.
cc
cc                         Synonyms:  [brick, br], [cluster, cl],
cc                         [cylinder, cyl],
cc                         [distance, dist, int, inter, intersect],
cc                         [ellipsoid, el, ell, ellipse], [help, h],
cc                         [hyperb, saddle], [line, l, ln], [plane, pl],
cc                         [point, p, pnt, pt], [proximal, prox],
cc                         [quadric, q, quad], [sphere, sph],
cc                         [tetrahedron, tet, tetra], [triangle, tri],
cc                         [zone, z, zn].

cc    distance           An option in command "variable", to use the value of
cc                         the last distance found with commands "distance",
cc                         "proximal", "side", "track" or "walk".
cc                         In the case of command "distance", the distance
cc                         between any two quadric surfaces, including planes,
cc                         is the distance to an external tangency, even if the
cc                         surfaces intersect.

cg    distance to collision
cg                       See "mean free path".

cg    distribution       See "cosine-power", "exponential", "isotropic",
cg                         "linear", "Maxwellian", "normal", "Planck spectrum",
cg                         "power-law", "uniform", "Wien spectrum".
cg                         See commands "bin", "pdf", "point", "sample",
cg                         "variable", "vector".

cg    divide             To divide real or integer numbers, see commands
cg                         "variable", "icalc", "big".

cg    division           The division or slash character, "/".

cg    divisor            See "common divisor", "gcd".

cc    dk                 A synonym for disk.

cc    DKNAME             The name of an annular disk.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.
cc                         No disk name may be "+", "-", "all", "h", "help",
cc                         "list", "point" or "thru", begin with "!" or contain
cc                         ";".
cc                         Also referred to as DKNAME1, DKNAME2, DKNAME3, ...
cc                         Specified with command "disk".
cc
cc                         Annular disks may appear in commands:
cc                         copy, disk, delete, plane, point, rename.
cc                         Also see commands:  last, list, repack, search, sort.

cc    DMAX               In command "walk", the maximum distance a point is to
cc                         be randomly walked from its initial position, if it
cc                         is not walked a total path length of PATHMAX first.
cc                         May be integer, floating point or a variable.

cc    DMEAN              In command "walk", the mean free path of a point being
cc                         displaced by a random walk process.
cc                         May be integer, floating point or a variable.

cc    dms                An option in command "angles" to convert angles from or
cc                         to degrees, minutes and seconds.

cn    dms.mac            A macro file for converting from degrees in decimal
cn                         form to degrees, minutes and seconds.
cn                         In ~/work/geom/test .
cn                         Type "in dms.mac ?" for info.  See "deg.mac".

cc    do                 A command to begin a do loop.  Must be followed, after
cc                         any desired block of commands, by command "enddo".
cc                         See "do while".
cc
cc                         Note:  do not use the statement separator ";" on the
cc                         same line as this command.
cc
cc                         Do loops may be nested, with up to 16 levels.
cc
cc                         Note:  command "goto" may not be used to jump into or
cc                         out of a do loop.  While in a do loop, any commands
cc                         read from another input file must end with a command
cc                         to return to the same do loop.
cc
cc                         Forms include:
cc
ccin                       help do
ccin                       do [help]
ccin                       help enddo
ccin                       enddo help
cc
cc                           Display the command options.
cc
ccin                       do VARNAME [=] N1 N2 [INC|1]
cc
cc                           Begin a do loop, with loop variable VARNAME ranging
cc                           from N1 to N2 with increment INC (default 1).
cc                           Name VARNAME has the same restrictions as any named
cc                           variable.  Arguments N1, N2 and INC must be
cc                           integers or integer variables.  Argument INC may be
cc                           negative.  The value of VARNAME starts at N1, and
cc                           is incremented by INC each time command "enddo" is
cc                           executed, until it falls outside the range from N1
cc                           to N2.  Until that happens, all the commands
cc                           between the initial command "do" of this do loop
cc                           and its corresonding command "enddo" are executed,
cc                           for each value of VARNAME.
cc
cc                           To loop over a range of floating point values,
cc                           e.g. from X1 to X2, with an increment of DX,
cc                           use the following commands:
cc
cc                           s XRANGE = X2 - X1
cc                           s N2 = XRANGE / DX
cc                           s N2 = N2 + 1
cc                           s N2 = 1 int N2
cc                           s X = X1
cc                           do N = 1 N2
cc                             ...
cc                             s X = X + DX
cc                           enddo
cc
ccin                       enddo
cc
cc                           Repeat the current "do-enddo" block with loop
cc                           variable VARNAME incremented from its current value
cc                           N to N + INC, unless N + INC is not in the range
cc                           from N1 to N2.  N1, N2 and INC are arguments in
cc                           command "do".
cc
cc                         Synonyms:  [help, h].

cg    do loop            A do loop consists of a block of commands beginning
cg                         with a "do VARNAME N1 N2 [INC|1]" command and ending
cg                         with an "enddo" command.  The loop variable VARNAME
cg                         will initially be set at value N1, and when command
cg                         "enddo" is reached, incremented by INC.  If the
cg                         value of VARNAME is still within the range from
cg                         N1 to N2, the loop will be repeated, starting at the
cg                         command after the command "do" that initiated this
cg                         do loop.
cg
cg                         Arguments N1, N2 and INC must be integers or integer
cg                         variables.  Argument INC may be negative, and if not
cg                         specified, defaults to 1.  If loop variable VARNAME
cg                         does not already exist, it will be created, as if
cg                         command "variable VARNAME = N1" had been used,
cg                         with the same restrictions on VARNAME.
cg
cg                         A do loop will be executed 1 + (N2 - N1) / INC
cg                         times (rounded to an integer).  This is the trip
cg                         count.
cg
cg                         Do loops may be nested, with up to 16 levels.
cg                         Each do loop must have a unique loop variable name.
cg                         Each do loop must be entirely contained within the
cg                         next outer do loop.
cg
cg                         Do loops may contain if-endif blocks, which may also
cg                         be nested.  Each such if-endif block must be
cg                         entirely within its do loop, and may be used to end a
cg                         do loop based on some other criterion than the values
cg                         of VARNAME, N1 and N2.  See "do while".
cg                         Jumps outside the do loop block are allowed only if
cg                         a jump back into the same do loop block follows.
cg                         Jumps into a do loop block from outside the block
cg                         should never be used.
cg
cg                         Do loops may not contain any of the following
cg                         commands or command synonyms:
cg                         ".", "call", "goto", "i", "in", "indo", "input",
cg                         "r", "rd", "read", "return", "rtn", "u", "undo".

cg    do loop use        Typically, use of do loops involves specifying an
cg                         initial set of objects with subscripted names, then
cg                         using a do loop over a range of values of the
cg                         suscripts to modify the values of the objects and use
cg                         the modified values to create additional objects with
cg                         or without subscripted names.  When the objects have
cg                         names with multiple subscripts representing, for
cg                         example, coordinate directions, two or more do loops
cg                         may be nested.
cg
cg                         Do loops may be used in place of certain commands,
cg                         including those with options for creating a group of
cg                         objects, including the options "brick", "concentric",
cg                         "family", "incr", "increment", "nest", "move",
cg                         "parallel", "rotate", "scale", "series", used in
cg                         one or more of the commands "cone", "cylinder",
cg                         "ellipsoid", "line", "plane", "quadric", "sphere",
cg                         "tetrahedron", "variable", "vector" and "zone".

cg    do until           See "do while".

cg    do while           The equivalent of a "do while" or "do until" loop may
cg                         be done by using an if-endif block within a do loop
cg                         executed with commands "do" and "enddo", placed
cg                         just before the "enddo" command, to reset the do loop
cg                         index outside its initial range.
cg
cg                         For example, a "do while x .ge. 1.e-12" loop or a
cg                         "do until x .lt. 1.e-12" loop might look like:
cg
cg                           do n 1 100
cg                             ...
cg                             if x .lt. 1.e-12
cg                               variable nlast = n
cg                               variable n = 101
cg                             endif
cg                           enddo
cg
cg                         Note the method of saving the last do loop index
cg                         used before exiting the loop.

cd    doc                Directory for documentation of GEOM.
cd                         Open YANA Cluster:  ~edwards/work/geom/doc
cd                         Archives:  /users/u47/edwards/geom/doc
cd                         See "make", "test".

cg    dodecahedron       A regular dodecahedron has 20 vertices, 30 edges, and
cg                         12 equilateral pentagonal faces.
cg                         The edge length, face area, volume, radius of
cg                         inscribed sphere, dihedral angle and central edge
cg                         angle, for a circumscribed sphere radius of 1.0 are:
cg
cg                         edge    = 4.0 / (sqrt (3.0) + sqrt (15.0))
cg                                 = 0.7136441795462
cg                         area    = 0.25 * sqrt (25.0 + 10.0 * sqrt (5.0)) *
cg                                   edge^2
cg                                 = 0.8762185201985
cg                         volume  = 0.25 * (15.0 + 7.0 * sqrt (5.0)) * edge^3
cg                                 = 2.785163863123
cg                         rinsc   = sqrt ((5.0 + 2.0 * sqrt (5.0)) / 15.0)
cg                                 = 0.7946544722918
cg                         angdih  = acos (-1.0 / sqrt (5.0))
cg                                 = 116.5650511771
cg                         angcent = acos (sqrt (5.0) / 3.0)
cg                                 = 41.81031489578
cg
cg                         See "polyhedron".

cg    dollar             The dollar character, "$".

cg    dot                The period or dot character, ".".  See command "dot".
cg                         See "dot product".

cc    dot                An option in command "variable", to find the dot
cc                         product of two vectors.  See "dot product".
cc                         Synonyms:  [dot, inner].

cc    dot                Command to find the dot product of two vectors, the
cc                         angle between them, and its cosine.
cc
cc                         Command "dot" relates to objects:  symbol, vector.
cc
cc                         Forms include:
cc
ccin                       help dot
ccin                       dot [help]
cc
cc                           Display the command options.
cc
ccin                       dot VNAME1 VNAME2
cc
cc                           Find the dot (inner) product of vectors VNAME1 and
cc                           VNAME2, the included angle, in the current angle
cc                           units, and its cosine.
cc
cc                         Synonyms:  [dot, inner], [help, h].

cg    dot product        The dot (or inner or scalar) product of two vectors
cg                         A = (AX, AY, AZ) and B = (BX, BY, BX) is the scalar
cg                         C = A dot B = AX*BX + AY*BY + AZ*BZ.
cg                         C = |A| * |B| * cos (THETA), where THETA is the angle
cg                         between vectors A and B.
cg                         Note that A dot B = B dot A, and that the dot product
cg                         of two perpendicular vectors is zero.

cg    double             In output from commands "root" and "roots", indicates
cg                         a root of order 2 of a polynomial equation.

cc    DPR                A uniform relative differential probability of a range
cc                         of values VRANL to VRANR of a random variable,
cc                         in command "bin".  Must not be negative.
cc                         See "PRTOT", "DPRL", "DPRR".

cc    DPRL               A relative differential probability of a value VRANL
cc                         of a random variable in command "bin".
cc                         Varies linearly from DPRL at VRANL to DPRR at
cc                         VRANR.  Must not be negative.
cc                         See "PRTOT", "DPR", "DPRR".

cc    DPRR               A relative differential probability of a value
cc                         VRANR of a random variable in command "bin".
cc                         Varies linearly from DPRL at VRANL to DPRR at
cc                         VRANR.  Must not be negative.
cc                         See "PRTOT", "DPR", "DPRL".

cg    dsum               An invariant of a quadric surface, for translations and
cg                         rotations.  See "invariants of quadric".

cc    DT                 In command "accelerate", the increment in time to be
cc                         used between the initial and final times for which
cc                         path length, velocity and position are to be
cc                         displayed.  If not specified, defaults to zero.
cc                         See "TMIN", "TMAX".

cc    DU                 In command "vector" or "plane", a vector component,
cc                         in the x, rcyl or rsph direction, for a rectangular,
cc                         cylindrical or spherical coordinate system,
cc                         respectively.
cc                         May be integer, floating point or a variable.

cg    du                 An increment or distance or vector component in the
cg                         u coordinate direction, which may be x, rcyl or rsph,
cg                         depending on the current coordinate system.

cg    du12               The u component of the distance between the centers of
cg                         the first and second circles, displayed after command
cg                         "intcirc".

cc    dup                A synonym for copy.

cc    duplicate          A synonym for copy.

cg    duplicate          To duplicate an object, use command "copy".

cc    DV                 In command "vector" or "plane", a vector component,
cc                         in the y, theta or theta direction, for a
cc                         rectangular, cylindrical or spherical coordinate
cc                         system, respectively.
cc                         May be integer, floating point or a variable.

cc    DV                 In command "slice", the increment between coordinate
cc                         values, for which points are to be found in a slice
cc                         of a quadric surface.  See "VMIN", "VMAX".

cg    dv                 An increment or distance or vector component in the
cg                         v coordinate direction, which may be y or theta,
cg                         depending on the current coordinate system.

cg    dv12               The v component of the distance between the centers of
cg                         the first and second circles, displayed after command
cg                         "intcirc".

cg    dval               An increment in the value of a random variable which
cg                         ranges from VRANL to VRANR.  Must be positive.

cc    DW                 In command "vector" or "plane", a vector component,
cc                         in the z, z or phi direction, for a rectangular,
cc                         cylindrical or spherical coordinate system,
cc                         respectively.
cc                         May be integer, floating point or a variable.

cg    dw                 An increment or distance or vector component in the
cg                         w coordinate direction, which may be z or phi,
cg                         depending on the current coordinate system.

cc    DX                 In command "root", the increment between successive
cc                         trial values of x, to search for roots, extrema
cc                         and inflection points of a polynomial equation using
cc                         Newtonian iteration.  No more than two roots,
cc                         extrema or inflection points can be found in each
cc                         increment DX.  Will be changed if either XMIN or
cc                         XMAX is changed to be within a calculated range of
cc                         x that contains all roots, extrema and inflection
cc                         points.
cc                         See "XMIN", "XMAX".

cg    dx                 An increment or distance or vector component in the
cg                         x coordinate direction.

cg    dy                 An increment or distance or vector component in the
cg                         y coordinate direction.

cg    dz                 An increment or distance or vector component in the
cg                         z coordinate direction.

E-------------------------------------------------------------------------------

cg    E                  See "E, e, E+, e+".

cg    e                  See "E, e, E+, e+".

cg    E+                 See "E, e, E+, e+".

cg    e+                 See "E, e, E+, e+".

cg    E, e, E+, e+       When preceded and followed by integers, indicates
cg                         multiplication by the power of ten indicated by the
cg                         final  integer.

cg    E-                 See "E-, e-".

cg    e-                 See "E-, e-".

cg    E-, e-             When preceded and followed by integers, indicates
cg                         division by the power of ten indicated by the final
cg                         integer.

cc    ebase              An option in command "symbol", argument SYMBNAME,
cc                         to create symbol ebase with value exp (1) =
cc                         2.71828182845904523536028747135266249775724709369995
cc                         Store as a big integer with command "input big.mac",
cc                         with file big.mac in the same directory as GEOM.

cg    ebase              The base of natural logarithms 2.718281828459045...
cg                         Generated as a symbol at the beginning of a
cg                         GEOM run.  ebase = exp (1).

cg    eccentricity       The eccentricity e of a hyperbola or a hyperbolic
cg                         cylinder is sqrt (1 + (B / A)^2), where
cg                         A is the transverse semiaxis, between the two
cg                         vertices, and B is the conjugate semiaxis, between
cg                         the two points where a line tangent to the vertices
cg                         intersects the asymptotes of the hyperbola.
cg
cg                         For the hyperbola or hyperbolic cylinder
cg                         QC + QXX * x^2 + QYY * y^2 = 0
cg                         (QXX > 0, QYY < 0)
cg                         the eccentricity is
cg                         sqrt (1 - QYY / QXX) > 1, if QC > 0 or
cg                         sqrt (1 - QXX / QYY) > 1, if QC < 0.
cg
cg                         The eccentricity e of an ellipse or elliptic cylinder
cg                         is sqrt (1 - (B / A)^2), where A is the major
cg                         semiaxis, and B is the minor semiaxis.
cg
cg                         For the ellipse or elliptic cylinder
cg                         QC + QXX * x^2 + QYY * y^2 = 0
cg                         (QC < 0, QXX => QYY > 0),
cg                         the eccentricity is sqrt (1 - QYY / QXX) < 1.
cg
cg                         For the ellipsoid
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0
cg                         (QC < 0, QXX => QYY => QZZ),
cg                         the eccentricities in planes of constant x, y and z
cg                         are sqrt (1 - QZZ / QYY), sqrt (1 - QZZ / QXX), and
cg                         sqrt (1 - QYY / QXX), respectively.

cg    echo               Each non-null input line is echoed in the output file,
cg                         preceded by the character ">", and if the input
cg                         medium is not the user's terminal, is echoed on the
cg                         user's terminal.

cc    edge               An option in command "trig", indicating that the next
cc                         argument is the positive length of a edge of a
cc                         triangle.  Synonyms:  [edge, side].

cg    edge               An edge of the mesh or the mesh block occurs wherever
cg                         two of the three mesh indices k, l and m have either
cg                         their minimum or maximum value, and the other index
cg                         ranges from its minimum to its maximum value.
cg                         The mesh and the mesh block each have 12 edges.
cg
cg                         To display the 12 edge lengths of a brick, use
cg                         command "brick".
cg                         The edges of a brick in the u, v and w directions
cg                         are labeled "min, min", "min, max", "max, min" and
cg                         "max, max", indicating the values of the other two
cg                         coordinates.  For example, in spherical coordinates,
cg                         edge phi (max, min) refers to the edge in the polar
cg                         angle phi direction, at maximum rsph, minimum theta.
cg
cg                         To display the edge length of a regular polygon,
cg                         use command "polygon".
cg
cg                         To display the average edge length of a general
cg                         polygon, use command "area".
cg
cg                         To display the edge length of a regular polyhedron,
cg                         use command "polyhedron".
cg
cg                         To find the plane containing the edge of a quadric
cg                         surface, as viewed from a point, use command "plane",
cg                         option "outline".

cg    edges              See "three edges", "triangle solution".

cg    edit               To display and/or edit a file, use the UNIX text
cg                         editor VI or GEOM command "vi".
cg                         For example, the saved input lines in file geom_cmd
cg                         could be edited to do a different problem, or to
cg                         correct errors before repeating a problem.

cd    edwards            Directory for Arthur L. Edwards, L-298, Ph. 422-4123
cd                         Open YANA Cluster:  ~edwards
cd                         Archives:  /users/u47/edwards

cc    el                 A synonym for ellipsoid.

cg    element            See "point element", "line element", "surface element",
cg                         "volume element", for elements of a mesh.

cg    element            See "brick", "tetrahedron", "zone".

cc    ell                A synonym for ellipsoid.

cc    ELL(1)             In command "ellipsoid", the name of a base ellipsoid,
cc                         used to create a family of ellipsoids.

cg    ellipse            An ellipse is a plane curve, for which the standard
cg                         equation in the x-y plane is:
cg                         - 1 + QXX * x^2 + QYY * y^2 = 0
cg                         (QXX => QYY).
cg                         The major semiaxis SAY = 1 / sqrt (QYY), and the
cg                         minor semiaxis SAX = 1 / sqrt (QXX).
cg                         The area is pi * SAX * SAY.
cg                         The perimeter requires an elliptic integral.

cc    ellipse            A synonym for ellipsoid.
cc                         Also see "cylinder, elliptic".

cg    ellipsoid          An ellipsoid is a quadric surface in 3-D space,
cg                         described by an implicit quadric equation.
cg                         An ellipsoid is a closed surface, with three axes.
cg                         An ellipsoid is axially symmetric if two of the three
cg                         axes are equal, and is a prolate spheroid if the
cg                         unequal axis is longer or an oblate spheroid if the
cg                         unequal axis is shorter.
cg
cg                         The standard forms of the implicit equations for
cg                         ellipsoids (with all coefficients positive) are:
cg
cg                         Real ellipsoid:
cg                                   - 1 + QXX*x^2 + QYY*y^2 + QZZ*z^2 = 0
cg                         Real sphere:
cg                                       - 1 + QXX * (x^2 + y^2 + z^2) = 0
cg                         Imaginary ellipsoid:
cg                                     1 + QXX*x^2 + QYY*y^2 + QZZ*z^2 = 0
cg                         Imaginary sphere:
cg                                         1 + QXX * (x^2 + y^2 + z^2) = 0
cg
cg                         The semiaxes in the x, y and z directions are
cg                         SX = 1/sqrt(QXX), SY = 1/sqrt(QYY), SZ = 1/sqrt(QZZ).
cg                         So, for a real ellipsoid, the standard equation is:
cg                              (x/SX)^2 + (y/SY)^2 + (z/SZ)^2 = 1
cg
cg                         For a real ellipsoid aligned with the x, y and z
cg                         axes, the eccentricities in the major planes are:
cg                         sqrt (1 - QZZ / QYY) or sqrt (1 - QYY / QZZ),
cg                         sqrt (1 - QZZ / QXX) or sqrt (1 - QXX / QZZ),
cg                         sqrt (1 - QYY / QXX) or sqrt (1 - QXX / QYY),
cg                         (use the positive argument of the square root).
cg
cg                         The distance D from the center to the surface in the
cg                         direction of any unit vector U = (UX, UY, UZ) is:
cg                           D = 1 / sqrt ((UX/SX)^2 + (UY/SY)^2 + (UZ/SZ)^2)
cg                         and the corresponding surface point P is:
cg                           P = (X, Y, Z) = (UX * D, UY * D, UZ * D).
cg
cg                         An ellipsoid centered on the z axis, at Z0, and
cg                         symmetric around the z axis (QXX = QYY), and passing
cg                         through the two points (R1, Z1) and (R2, Z2), where
cg                         R1^2 = X1^2 + Y1^2, and R2^2 = X2^2 + Y2^2,
cg                         has the equation:
cg                           QC + QXX * (x^2 + y^2) + QZZ = 0
cg                         where w = R2^2*(Z1-Z0)^2 - R1^2*(Z2-Z0)^2,
cg                         A1 = (R2^2 - R1^2) / w
cg                         A2 = [(Z1 - Z0)^2 - (Z2 - Z0)^2] / w
cg                         QC = -1 / sqrt(A2)
cg                         QZZ = A1 / A2
cg                         This requires that w not be zero, Z1 not be equal to
cg                         Z2, and that the point further from Z0 have the
cg                         smaller value of R.
cg
cg                         In a command, the word "ellipsoid" means a real
cg                         ellipsoid.   Otherwise, use "quadric".
cg
cg                         To find the distance from a point to an ellipsoid,
cg                         use command "distance", "proximal" or "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and an ellipsoid, use command "distance".
cg
cg                         The following commands relate to ellipsoids:
cg                         accelerate, arc, axisym, copy, debug, delete,
cg                         distance, ellipsoid, extrema, help, invert, last,
cg                         list, move, operator, point, proximal, quadric,
cg                         reflect, rename, repack, rotate, scale, search, side,
cg                         slice, sort, symbol, synonym, tables, track, triple,
cg                         vector, zone.

cc    ellipsoid          Command to display or create ellipsoids.
cc                         Creating an ellipsoid replaces any existing quadric
cc                         surface having the same name.
cc                         The normal vectors will be radially outward.
cc                         See "quadric" for other options.
cc                         See "do loop use".
cc
cc                         Command "ellipsoid" relates to objects:  axisym,
cc                         ellipsoid, operator, point, quadric, symbol,
cc                         variable, vector.
cc
cc                         Forms include:
cc
ccin                       help ellipsoid
ccin                       ellipsoid [help]
cc
cc                           Display the command options.
cc
ccin                       ellipsoid [all,list]
cc
cc                           Display all ellipsoids (short display).
cc
ccin                       ellipsoid list ELNAME1 ELNAME2 ELNAME3 ...
cc
cc                           Display ellipsoids ELNAME1, ELNAME2, ELNAME3, ...,
cc                           with or without subscripts (short display).
cc
ccin                       ellipsoid ELNAME
cc
cc                           Display ellipsoid ELNAME (long display).
cc
cc                         In the following commands, use "+" or "-" instead of
cc                         ELNAME or ELL(2) to form the name by incrementing or
cc                         decrementing the base name for ellipsoids.
cc                         See command "last", "increment names".
cc
ccin                       ellipsoid ELNAME = PCEN SAX SAY SAZ
cc
cc                           Create ellipsoid ELNAME, centered at point PCEN,
cc                           with semiaxes SAX, SAY and SAX in the x, y and z
cc                           directions, respectively.
cc                           Note:  if any semiaxis is given a very large value,
cc                           such as 10^99, the resulting quadric surface will
cc                           be an elliptic cylinder, not an ellipsoid.
cc
ccin                       ellipsoid ELNAME fit PCEN VAXIS PNAME2 PNAME3
cc
cc                           Create circular ellipsoid ELNAME, centered at point
cc                           PCEN, with axis vector VAXIS, and passing through
cc                           the two points PNAME2 and PNAME3.  This is an
cc                           axially symmetric quadric surface, which may be an
cc                           oblate or prolate spheroid.
cc
ccin                       ellipsoid ELL(2) move NUMELL INC ELL(1) VMOVE
cc
cc                           Create a family of NUMELL ellipsoids ELL(2), ...,
cc                           with names incremented by INC characters, spaced at
cc                           intervals of vector VMOVE, starting from ellipsoid
cc                           ELL(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       ellipsoid ELL(2) rotate NUMELL INC ELL(1) OPNAME PINV
cc
cc                           Create a family of NUMELL ellipsoids ELL(2), ...,
cc                           with names incremented by INC characters, by
cc                           rotating the preceding ellipsoid with operator
cc                           OPNAME and invariant point PINV, starting from
cc                           ellipsoid ELL(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
ccin                       ellipsoid ELL(2) scale NUMELL INC ELL(1) OPNAME PINV
cc
cc                           Create a family of NUMELL ellipsoids ELL(2), ...,
cc                           with names incremented by INC characters, by
cc                           scaling the preceding ellipsoid with operator
cc                           OPNAME and invariant point PINV, starting from
cc                           ellipsoid ELL(1).  See "increment names".
cc                           See command "quadric" for an equivalent set of
cc                           commands using subscripted names and a do loop.
cc
cc                         Synonyms:  [help, h], [ellipsoid, el, ell, ellipse],
cc                         [move, mv, trans, translate], [rotate, rot].

cc    ellipsoid          An option in commands "copy", "delete", "last", "list",
cc                         "rename", "repack" and "sort", to perform the
cc                         specified operation on one or more ellipsoids.
cc                         Synonyms:  [ellipsoid, el, ell, ellipse].

cg    ellipsoid arrays   Ellipsoids may be created as arrays with subscripted
cg                         names.  See "subscript", "subscripted names",
cg                         commands "do" and "enddo".

cg    ellipsoids         A family of ellipsoids may be created with command
cg                         "ellipsoid", options "move", "rotate" or "scale"
cg                         (with restrictions) or as follows:
cg
cg                         p pinv (options)
cg
cg                           Create an invariant point, if needed.
cg
cg                         ell ELL(1) (options)
cg
cg                           Create a base ellipsoid.
cg
cg                         op opr (options)
cg
cg                           Create a tensor operator, to reflect, rotate,
cg                           invert or scale, if needed.
cg
cg                         v vmove (options)
cg
cg                           Create a vector for use as a translation operator,
cg                           if needed.
cg
cg                         cp ELL(1) ELL(2)
cg
cg                           Copy ellipsoid ELL(1) to the first ellipsoid.
cg
cg                         Repeat the following block of commands as many times
cg                         as needed to create the rest of the family of
cg                         ellipsoids.  See "shortcuts".
cg
cg                         mv ell ELL(1) vmove
cg
cg                           Move the base ellipsoid by amount move, if needed.
cg
cg                         [invert,reflect,rotate,scale] ell ELL(1) opr [pinv]
cg
cg                           Invert, reflect, rotate or scale the base ellipsoid
cg                           with tensor operator opr, if needed.
cg
cg                         cp ell ELL(1) +
cg
cg                           Copy the base ellipsoid to the next ellipsoid.

cg    elliptic           See "elliptic cone", "elliptic cylinder",
cg                         "elliptic paraboloid".

cg    elliptic cone      An elliptic cone is a quadric surface for which the
cg                         standard equation is:
cg                           x^2 + QYY*y^2 - |QZZ|*z^2 = 0, (QYY>0, QZZ<0).
cg                         An imaginary elliptic cone is a quadric surface for
cg                         which the standard equation is:
cg                           x^2 + QYY*y^2 + QZZ*z^2 = 0, (QYY>0, QZZ>0).
cg                         This last equation is also satisfied at the real
cg                         point (0,0,0).
cg
cg                         To find the distance from a point to an elliptic
cg                         cone, use command "distance", "proximal" or "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and an elliptic cone, use command "distance".

cg    elliptic cylinder
cg                       An elliptic cylinder is a quadric surface for which the
cg                         standard equation is:
cg                          - 1 + QXX*x^2 + QYY*y^2 = 0, (QXX>0, QYY>0).
cg                         An imaginary elliptic cylinder is a quadric surface
cg                         for which the standard equation is:
cg                            1 + QXX*x^2 + QYY*y^2 = 0.  (QXX>0, QYY>0).
cg
cg                         To create an elliptic cylinder aligned with the x,
cg                         y or z axis, use command:
cg
cg                         ellipsoid QNAME = PCEN SAX SAY SAZ
cg
cg                           Create elliptic cylinder QNAME, centered at point
cg                           PCEN, with semiaxes SAX, SAY and SAX (one of which
cg                           is very large, say 10^99) in the x, y and z
cg                           directions, respectively.  Any future reference to
cg                           this quadric surface must use option "quadric", not
cg                           "ellipsoid".
cg
cg                         To find the distance from a point to an elliptic
cg                         cylinder, use command "distance", "proximal" or
cg                         "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and an elliptic cylinder, use command "distance".

cg    elliptic paraboloid
cg                         An elliptic paraboloid is a quadric surface for which
cg                         the standard equation is:
cg                               -QZ*z + x^2 + QYY*y^2 = 0.
cg
cg                         To find the distance from a point to an elliptic
cg                         paraboloid, use command "distance", "proximal" or
cg                         "side".
cg
cg                         To find the distance or intersection between a plane
cg                         and an elliptic paraboloid, use command "distance".

cc    ELNAME             The name of an ellipsoid.  May have up to 24
cc                         characters, and may be ASCII, integer or floating
cc                         point.  May not be the same as any other quadric
cc                         surface name QNAME.  Also referred to as ELNAME1,
cc                         ELNAME2, ...  Specified with command "ellipsoid".
cc                         No ellipsoid name may be "+", "-", "all", "h",
cc                         "help", "list" or "thru", begin with "!" or contain
cc                         ";".
cc
cc                         Ellipsoids may appear in commands:
cc                         accelerate, arc, axisym, cone, copy, delete,
cc                         distance, ellipsoid, extrema, help, invert, last,
cc                         list, move, operator, point, project, proximal,
cc                         quadric, reflect, rename, repack, rotate, scale,
cc                         search, side, slice, sort, track, triple, vector.

cg    embedded           See "embedded lines".

cg    embedded lines     At any point on some quadric surfaces (all planes,
cg                         cylinders, cones, hyperbolic paraboloids, and
cg                         hyperboloids of one sheet) one or more straight lines
cg                         can be drawn, lying entirely on the surface.
cg                         These quadric surfaces are ruled surfaces.
cg                         See "ruled surface".
cg                         See commands "arc" and "hyperb".

cg    encryption         Encryption is the process of making data or a text
cg                         unreadable without special knowledge, intended to
cg                         be available only to certain recipients.
cg                         See command "big".

cg    end                See "end of command", "end of comment".

cc    end                Command to end the current run.
cc                         Synonyms:  [end, exit, quit, split].

cg    end of command     The unquoted character ";" ends a command or a comment,
cg                         when multiple commands and/or comments are on one
cg                         input line.  Ignored if between single or double
cg                         quotes (as in commands "alias", "define" and
cg                         "marker").  Does not need to be delimited.
cg                         If not between single or double quotes, will
cg                         terminate a comment, allowing a command to follow on
cg                         the same line.  Ignored in command "hex".
cg                         Can not be used after commands "indo", "input",
cg                         "read", "redo", "return" or"undo", because chaos
cg                         might ensue.

cg    end of comment     The unquoted character ";", if not between single or
cg                         double quotes, will terminate a comment, allowing a
cg                         command to follow on the same line.  Does not need to
cg                         be delimited.

cg    end-of-file        An end-of-file in the input file will have the same
cg                         effect as command "return" or "input #".

cc    enddata            An option in command "variable", indicating the end
cc                         of a table of variable values.  See "data".

cc    enddo              A command to repeat or end a do loop.  Must be preceded
cc                         by command "do".  Amy desired block of commands may
cc                         be used in between command "do" and command "enddo",
cc                         including other do loops.  See "do while".
cc
cc                         Note:  do not use the statement separator ";" on the
cc                         same line as this command.
cc
cc                         Note:  "do-enddo" blocks of commands may be nested.
cc
cc                         Forms include:
cc
ccin                       help enddo
ccin                       enddo help
cc
cc                           Display the command options.
cc
ccin                       enddo
cc
cc                           Repeat the current "do-enddo" block for loop
cc                           variable VARNAME incremented from its current value
cc                           N to N + INC, unless N + INC is not in the range
cc                           from N1 to N2.  N1, N2 and INC are arguments in
cc                           command "do".
cc
cc                         Synonyms:  [help, h].

cc    endif              The final command in an "if-endif" block of input
cc                         lines, which must begin with command "if ...".
cc
cc                         Command "endif" relates to objects:  symbol.
cc
cc                         Forms include:
cc
ccin                       help endif
ccin                       endif help
cc
cc                           Display the command options commands "if" and
cc                           "endif".  Note that the argument "help" is not
cc                           optional.
cc
ccin                       endif
cc
cc                           End the current "if-endif" block of input lines,
cc                           which begins with the command "if" defining the
cc                           current "if-endif" block.
cc
cc                         Synonyms:  [help, h].

cg    English            Commands and options in GEOM are based on English.
cg                         See "language".

cc    ENTRY              In command "define", the name of the entry in geom_base
cc                         (this file) to be displayed.  Must be bracketed by
cc                         single (') or double (") quotes.
cc                         If ENTRY is bracketed by single quotes, double any
cc                         internal single quotes.
cc                         If ENTRY is bracketed by double quotes, double any
cc                         internal double quotes.
cc                         The entry is found by matching columns 7-25 in
cc                         this file, geom_base, ignoring case, with ENTRY.
cc                         All lines are displayed until the next non-matching
cc                         entry.  Multiple entries with the same name will be
cc                         displayed.  ENTRY may have up to 19 characters.

cg    entry              In this file, a section delimited by blank lines, with
cg                         the name of the entry in columns 7-24 of the first
cg                         line.

cc    env                A synonym for environment.

cg    environment        See "environmental", command "environment".

cc    environment        An option in command "debug", to display GEOM internal
cc                         variables for the environment:
cc                         alodmach, aloddate, alodtime, aversion, amach,
cc                         adate, atime, atitle, aprompt, aprompts, lprompts.
cc                         Synonyms:  [environment, env, setup].

cc    environment        An option in command "help", to display a help message
cc                         for environment commands.

cc    environment        Command to display a help message for environment
cc                         commands, which include:
cc                         alias, angles, binary, commands, coordinate, dec,
cc                         define, degrees, delimiter, end, endif, help, hex,
cc                         icalc, if, indo, input, marker, nobin, oct, output,
cc                         page, plot, prompt, radians, redo, status, symbol,
cc                         synonym, tables, time, title, tol, tol, trace, undo,
cc                         variable, vi, when.
cc
cc                         Forms include:
cc
ccin                       help environment
ccin                       environment [help]
cc
cc                           Display a help message for environment commands.
cc
cc                         Synonyms:  [help, h], [environment, env, setup].

cg    environmental      To specify, create, display and use environmental
cg                         objects, see the entries and commands:  ".", ";",
cg                         alias, angles, binary, commands, coordinate, debug,
cg                         dec, define, degrees, delim, end, endif, help, hex,
cg                         icalc, if, indo, input, marker, nobin, oct, output,
cg                         page, plot, prompt, radians, redo, status, symbol,
cg                         synonym, tables, time, title, tol, tol, trace, undo,
cg                         variable, vi, when.

cg    equal              See "equal temperament", "equal zoning",
cg                         "equally-tempered".

cg    equal sign         The equal sign, "=".

cg    equal temperament
cg                       See "equally-tempered".

cg    equal zoning       Planes or other quadric surfaces may be created in a
cg                         family in which each surface is displaced by a
cg                         specified constant amount from the preceding surface,
cg                         in a specified direction.
cg                         Points may be created in a family in which each point
cg                         is displaced by a specified constant amount from the
cg                         preceding point, in a specified direction.
cg                         See option "move" of commands "point", "sphere",
cg                         "cylinder", "cone", "axisym", "quadric", and see
cg                         command "plane", option "parallel".
cg                         See "ratio zoning".
cg
cg                         Points may be created in a 3-D array in a brick,
cg                         in such a way that the volumes of each of the
cg                         smallest elements with 8 points at their vertices are
cg                         equal.  See command
cg                         "point PMESH brick BRNAME mesh bloxk [volume]".
cg                         See "briquette".
cg
cg                         See "do loops" and commands "do" and "enddo".

cg    equally-tempered   A musical scale in which adjacent semitones have a
cg                         fixed frequency ratio, 2^(1/12) = 1.059463094359.
cg                         For one octave, the results are as follows:
cg
cg                         Note  Equal-temp   Value  Just    Cents   Interval
cg                               ratio        cents  ratio   diff
cg
cg                          1  1.000000000000     0   1/1     0      unison
cg                          2  1.059463094359   100  16/15  -11.731  semitone
cg                          3  1.122462048309   200   9/8     3.910  whole tone
cg                          4  1.189207115003   300   6/5   -15.641  minor 3rd
cg                          5  1.259921049895   400   5/4    13.686  major 3rd
cg                          6  1.334839854170   500   4/3     1.955  perfect 4th
cg                          7  1.414213562373   600  45/32    9.776  tritone
cg                          8  1.498307076877   700   3/2    -1.955  perfect 5th
cg                          9  1.587401051968   800   8/5   -13.687  minor 6th
cg                         10  1.681792830507   900   5/3    15.641  major 6th
cg                         11  1.781797436281  1000  16/9     3.910  minor 7th
cg                         12  1.887748625363  1100  15/8    11.731  major 7th
cg                         13  2.000000000000  1200   2/1      0     octave
cg
cg                         Note  Equal-temp   Just ratio
cg                               ratio
cg
cg                         A   1.000000000000  1.00000
cg                         Bb  1.059463094359  1.06667
cg                         B   1.122462048309  1.12500
cg                         C   1.189207115003  1.20000
cg                         Db  1.259921049895  1.25000 or 1.26562 = 81/64
cg                         D   1.334839854170  1.33333
cg                         Eb  1.414213562373  1.40625 or 1.42383 = 729/512
cg                         E   1.498307076877  1.50000
cg                         F   1.587401051968  1.60000
cg                         Gb  1.681792830507  1.66667 or 1.68750 = 27/16
cg                         G   1.781797436281  1.77778
cg                         Ab  1.887748625363  1.82500 or 1.89844 = 243/128
cg                         A   2.000000000000  2.00000
cg
cg                         See "piano", "cents".

cg    equation           The real and/or complex roots of a quadratic
cg                         (a3 = a4 = 0), cubic (a4 = 0) or quartic polynomial
cg                         equation of the form:
cg                           a0 + a1 * z + a2 * z^2 + a3 * z^3 + a4 * z^4 = 0
cg                         may be found with command "roots".
cg
cg                         The real coefficients a0, a1, a2, a3 and a4 may be
cg                         found for any specified set of from two to four real
cg                         and/or complex roots with command "roots", option
cg                         "=".
cg
cg                         To search for real roots, extrema and inflection
cg                         points of a polynomial equation using Newtonian
cg                         iteration, use command "root".
cg
cg                         To find the coefficients of an Nth-order polynomial
cg                         equation with N specified real roots, use command
cg                         "root", option "=".

cg    equations          See "polygon equations", "polynomial", "quadric types",
cg                         "quadric curves", command "solve".

cg    equilateral        For every triangle, there are equilateral triangles
cg                         that have a parallel projection onto the triangle.
cg                         Whenever the data for a triangle are displayed, the
cg                         vertex coordinates and edge length of one such
cg                         triangle, such that one vertex is shared, are
cg                         displayed.

cc    err                A synonym for error.

cg    err                Estimated numerical truncation error in calculating
cg                         a value, based on TOL.  See "error estimate".

cg    error              Error messages are generated by the code whenever it
cg                         detects an error in an input line, which may include
cg                         an unrecognized command, the wrong number, mode or
cg                         sign of arguments, or the non-existence of an
cg                         operator, geometric object, file or key word referred
cg                         to in the command, or the non-existence of a
cg                         result satisfying the requirements of the command.
cg                         After an error message, check the command, or type
cg                         "help COMMAND" to display the options, or type
cg                         "define 'ENTRY'" to display the entry in geom_base
cg                         for ENTRY, and retry.
cg                         Use command "trace" to display the return path from
cg                         the current input file.
cg                         See command "error".

cc    error              Command to display a help message for error control
cc                         commands, which include: undo, indo, redo, input.
cc
cc                         Forms include:
cc
ccin                       help error
ccin                       error [help]
cc
cc                           Display a help message for error control commands.
cc
cc                         Synonyms:  [error, err], [help, h].

cc    error              An option in command "help", to display help messages
cc                         for error control commands.

cg    error              See "error estimate", "truncation error".

cg    error control      See commands "debug", "indo", "input", "parse", "redo",
cg                         "return", "symbol", "undo".
cg                         If you have ended the run, see "input file",
cg                         to find how to make a new input file to repeat
cg                         the run without the error(s).

cg    error correction   See "error control".

cg    error estimate     When calculating a value Z(A, B, C, ...), a function of
cg                         A, B, C, ..., a first-order estimate of the error
cg                         in Z, E(Z), is given by:
cg                         E(Z) = abs (Z'(A)) * E(A) + abs (Z'(B)) * E(B)
cg                                + abs (Z'(C)) * E(C) + ... ,
cg                         where Z'(A), Z'(B), Z'(C), ... are the partial
cg                         derivatives of Z with respect to A, B, C, ..., and
cg                         E(A), E(B), E(C), ... are the (positive) estimated
cg                         errors in A, B, C, ...
cg                         For an input value A, the estimated error E(A) is
cg                         TOL * abs (A).

cg    escape character   A character used to force the following character to be
cg                         interpreted literally, instead of having a special
cg                         meaning or function.  For example, adding an extra
cg                         quote mark to a quote mark inside of a quoted
cg                         character string or prefixing a character with a
cg                         backslash "\" or <control-V> in the text editor VI.

cg    estimate           To estimate the volume of a zone by a Monte Carlo
cg                         method, use command "mcvol".

cc    Euler              A synonym for euler.

cg    Euler              See "Euler's Totient", "totient function".

cc    euler              An option in command "symbol", argument VNAME,
cc                         to create symbol euler with value
cc                         0.57721566490153386061...
cc                         Store as a big integer with command "input big.mac",
cc                         with file big.mac in the same directory as GEOM.

cg    euler              Euler's constant.  Generated as a symbol at the
cg                         beginning of a GEOM run.
cg                         euler = the limit as z approaches infinity of
cg                                 1 + 1/2 + 1/3 + 1/4 + ... + 1/z - log z =
cg                         euler = 0.57721566490153386061...
cc                         Store as a big integer with command "input big.mac",
cc                         with file big.mac in the same directory as GEOM.

cg    Euler's            See "Euler's Totient", "totient function".

cg    Euler's Totient    See "totient function".

cg    eV                 Electron volts (an energy unit).
cg                         1 amu = 9.3149432E8 eV (+/- 0.3 ppm).
cg                         1 K = 8.617385E-5 eV (+/- 8.5 ppm).
cg                         1 Hz = 4.1356692E-15 eV (+/- 0.3 ppm).

cc    event              An option in command "bin", to create a probability
cc                         bin for a discrete event, identified by the name of
cc                         the bin.

cc    exch               A synonym for exchange.

cc    exchange           An option in command "mesh", to exchange the layers in
cc                         the directions of two different indices in a mesh
cc                         block, and to redefine the mesh indices of any mesh
cc                         points in the mesh block accordingly.  The mesh block
cc                         must have the same size in the two layer directions.
cc                         Along with option "invert" in command "mesh", this
cc                         allows all possible mesh reflections and rotations
cc                         to be done.
cc                         Synonyms:  [exchange, exch].

cg    EXCHANGED          In the display for a point, indicates a mesh point in
cg                         a mesh block for which mesh indices have been
cg                         exchanged.

cg    excluded           See "excluded names".

cg    excluded names     Some names are disallowed for all or some object names,
cg                         because they make interpretation of a command
cg                         ambiguous.
cg                         No name may be "+", "-", "all", "h", "help",
cg                         "list" or "thru", begin with "!" or contain ";".
cg                         A point name must not be "cluster".
cg                         A cluster name must not be "point".
cg                         A quadric surface name must not be "types".

cg    exclusive          See "exclusive or", "Boolean".

cg    exclusive or       See "Boolean".

cg    execution          See "GEOM execution".

cc    execution line     See "GEOM execution".

cc    exit               A synonym for end.

cc    exp                An option in command "bin", to create an exponential
cc                         probability distribution function.

cc    exp                An option in command "variable", argument FUNCTION,
cc                         to indicate the base e exponential function.
cc                         A exp B means A * exp (B).

cc    exp                An option in command "big", to find a base e
cc                         exponential function of a specified argument,
cc                         in the form of a big integer.

cf    exp                The exponential function.  Example:  y = exp (x)
cf                         means y = e^x, where e is the base of natural
cf                         logarithms.

cg    expected           See "expected value".

cg    expected value     The expected value of a random variable v(x)^n with
cg                         a probability distribution p(x) from x1 to x2 is
cg                         <v^n>, and is equal to the integral from x1 to x2
cg                         of v(x)^n * p(x) * dx, divided by the integral from
cg                         x1 to x2 of p(x) dx.
cg                         The variance of v is <v^2> - <v>^2, and the
cg                         standard deviation of v is the square root of the
cg                         variance.
cg                         See "random walk", commands "bin", "pdf", "sample",
cg                         "spin", "walk".

cg    exponent           A floating point number may be represented by a
cg                         mantissa, e.g. 1.23456789, followed by an exponent
cg                         indicating a power of ten, e.g, e-3, e22, meaning
cg                         10^(-3) or 0.001 and 10^22, respectively.
cg                         See "E, e, E+, e+", "E-, e-".

cg    exponential        An exponential probability distribution is a type of
cg                         probability bin or probability distribution function
cg                         (pdf) for which the relative differential probability
cg                         is an exponential function of the value of the random
cg                         variable, for a specified range of such values.
cg                         See "discrete event", "discrete object",
cg                         "discrete value", "uniform", "linear", "power-law".
cg                         See commands "bin", "pdf", "sample".

cg    extend             To extend two sides of a triangle, to make a new
cg                         triangle with twice the area, and a perimeter twice
cg                         that of the extended sides, see command "cute".

cg    exterior           An exterior mesh point is one that has exactly one
cg                         nearest neighbor in one or more of the three mesh
cg                         index directions k, l and m.
cg                         An exterior mesh block point is one that has exactly
cg                         one nearest neighbor in the mesh block, in one or
cg                         more of the three mesh directions k, l and m.

cc    extr               A synonym for extrema.

cg    extr               In display from commands "side" and "distance",
cg                         indicates an extremum on the quadric surface in a
cg                         specified vector direction.  An estimate of the
cg                         proximal point on the quadric surface, nearest point
cg                         PNAME.

cg    extract            See "extract entries".

cg    extract entries    To extract entries from geom_base that contain any
cg                         desired key words, using UNIX command "grep":
cg
cg                         For a single key word KEYWORD1:
cg
cg                         grep -p KEYWORD1 geom_base >! OUT_FILE
cg
cg                           For each occurrence in file geom_base of the key
cg                           word KEYWORD1, write the entry containing KEYWORD1
cg                           into file OUT_FILE.
cg
cg                         For multiple key words KEYWORD1, KEYWORD2, ...:
cg
cg                         grep -p -f KEYWORD_FILE geom_base >! OUT_FILE
cg
cg                           For each occurrence in file geom_base of any of the
cg                           key words in file KEYWORD_FILE, write the entry
cg                           containing the key word into file OUT_FILE,
cg
cg                         where KEYWORD_FILE is a file containing all of the
cg                         key words, each on a single line.

cg    extrema            The extrema of a curve are any points on the curve,
cg                         for which the normal vector to the curve is parallel
cg                         to a specified axis in the plane of the curve
cg                         An extremum may be a maximum, a minimum or an
cg                         inversion point.
cg
cg                         To find the extrema of a quadric curve in a major
cg                         plane, use command "quadric" or "slice".
cg
cg                         The extrema of a polynomial equation in z = x + i*y,
cg                         P(z) = a0 + a1*z + a2*z^2 + a3*z^3 + a4*z^4 + ...
cg                         are at the roots of the derivative of the equation,
cg                         P'(z) = a1 + 2*a2*z + 3*a3*z^2 + 4*a4*z^3 + ...,
cg                         where the slope of the polynomial is zero.
cg                         See "quadratic", "cubic", "quartic".
cg                         See commands "root" and "roots".
cg
cg                         The extrema of a surface are any points or curves on
cg                         the surface, for which the normal vector to the
cg                         surface is parallel to a specified axis.  An extremum
cg                         may be a maximum, minimum or saddle point.
cg
cg                         To find the extrema in any specified direction on a
cg                         quadric surface, use command "quadric" or "extrema".
cg
cg                         If a quadric surface is defined by a second order
cg                         implicit equation F(x,y,z) = 0, then the family of
cg                         quadric surfaces represented by the function
cg                         F(x,y,z) = C may have extrema at points on a line
cg                         or a curve.  In general, such points or curves are
cg                         not proximal or distal to the extrema on the quadric
cg                         surface for which F = 0.
cg
cg                         See "proximal".

cc    extrema            Command to find the extreme points on one or all
cc                         quadric surfaces in a specified direction, and the
cc                         nature of the curvature of the surface at any such
cc                         points.  See command "arc".
cc
cc                         Command "extrema" relates to objects:  axisym, cone,
cc                         cylinder, ellipsoid, hyperb, plane, quadric, sphere,
cc                         symbol, vector.
cc
cc                         Forms include:
cc
ccin                       help extrema
ccin                       extrema [help]
cc
cc                           Display the command options.
cc
ccin                       extrema QNAME VNAME
cc
cc                           Find the extrema of quadric surface QNAME in the
cc                           direction of vector VNAME, and the nature of the
cc                           curvature of the surface and any such extrema.
cc
ccin                       extrema all VNAME
cc
cc                           Find the extrema of all quadric surfaces in the
cc                           direction of vector VNAME, and the nature of the
cc                           curvature of the surface and any such extrema.
cc
cc                         Synonyms:  [extrema, extr], [help, h].

cg    extreme            To find the extreme points of a quadric surface in a
cg                         specified direction, see command "extrema".

F-------------------------------------------------------------------------------

cg    F                  The general equation of a quadric surface is:
cg                         F(x,y,z) = 0.  See "quadric surface".

cc    F1-FN              Arguments in command "variable", to be added (option
cc                         "+"), multiplied (option "*"), or their reciprocals
cc                         added (option "/"), or to be assigned to a set of
cc                         variables (option "data").

cg    face               A face of the mesh or the mesh block occurs wherever
cg                         one of the three mesh indices k, l and m has either
cg                         its minimum or maximum value, and each of the other
cg                         two indices ranges from its minimum value to its
cg                         maximum value.  The mesh and the mesh block each have
cg                         six faces.

cc    FACT               An argument in command "quadric" option "*" or "/",
cc                         which will multiply or divide, respectively, the
cc                         coefficients of the implicit equation for a quadric
cc                         surface.
cc                         May be integer, floating point or a variable.

cc    fact               An option in command "big", to find the factorial
cc                         function of a specified big integer.

cc    fact               An option in commands "icalc" and "variable", to find
cc                         the factorial function (to be done on the following
cc                         argument, which must be a non-negative integer).

cg    factf.mac          A macro file for finding the prime factors of factorial
cg                         functions up to 1012!.  In ~/work/geom/test .

cg    factor             To find all of the prime factors of any integer N from
cg                         1 to 10^18 use command "factor".
cg                         See command "big", option "//".

cg    factor             See "prime factors", "scale factor", "view factor",
cg                         command "factor".

cc    factor             Command to find all of the prime factors and their
cc                         cofactors, for any specified positive integers M from
cc                         1 to 10^18 and for each M, to find the Euler's
cc                         totient function for modulo M arithmetic, which is
cc                         the number of integers in the set (1, ..., M - 1)
cc                         that are relatively prime to M (have no common
cc                         factors other than 1), and to find the number of
cc                         integers that do have common factors with M.
cc                         See "totient function" and "modular arithmetic".
cc
cc                         Command "factor" relates to objects:  symbol,
cc                         variable.
cc
cc                         Forms include:
cc
ccin                       help factor
ccin                       factor [help]
cc
cc                           Display the command options.
cc
ccin                       factor M1 M2 [thru] M3 ...
cc
cc                           For each integer M = M1, M2 [, through] M3, ...,
cc                           find all of the prime factors and their cofactors,
cc                           and find the number of integers in the set
cc                           (1, ..., M - 1) that are relatively prime to M
cc                           (have no common factors other than 1), and the
cc                           number of integers that do have common factors
cc                           with M.  M must be from 1 to 10^18.
cc                           Negative values are changed to positive.
cc
cc                         Synonyms:  [factor, totient], [help, h].

cg    factorial          The factorial function, defined only for non-negative
cg                         integers:  n! = 1, n! = 1 * 2 * 3 * ... * n.
cg
cg                         The average derivative of n! with respect to n is:
cg                         from n - 1 to n    :  n! * (1 - 1/n)
cg                         from n     to n + 1:  n! *  n
cg                         from n - 1 to n + 1:  n! * (n + 1 - 1/n) / 2
cg                         and at n, approximatly for very large n:
cg                                               n! * (n*log(n) + 1/2) / n
cg
cg                         The options in commands "icalc" and "variable" are:
cg
cg                         icalc M fact N
cg
cg                           Display M * N!.  With M = 1, limited to 19!, with
cg                           18 digits:  121645100408832000.
cg
cg                         variable VARNAME = A fact N
cg
cg                           Create variable VARNAME, equal to A * N!.
cg                           With A = 1.0, limited to 170!, with 307 digits:
cg                           7.25741561530799896739672821112926311471699E+306.
cg
cgin                       big BIGNAME = BIGNAME2 fact
cg
cg                           Create big integer BIGNAME, equal to BIGNAME2!.
cg                           With the current limit of 1001 digits for big
cg                           integers, limited to 450!, with 1001 digits:
cg                           1.733368733112632659344713146104579399677811E+1000.
cg
cg                         See "prime products".

cg    factorial          See "factorial factors".

cg    factorial factors
cg                       The factorial function of n, n!, has the factors
cg                         1 * 2 * 3 * ... * (n-1) * n.  This may also be
cg                         expressed using only prime numbers as factors.
cg
cg                         Command "factor" may be used to find the prime
cg                         factors of a factorial.
cg
cg                         variable VARNAME = A fact N
cg
cg                           Create variable VARNAME, equal to A * N!.
cg                           With A = 1.0, limited to 170!.
cg
cg                         factor VARNAME
cg
cg                           Display the prime factors of VARNAME.
cg
cg                         In the case of factorials that are too big to store
cg                         as integers in a particular computer, the prime
cg                         factors of n! may be found as follows:
cg
cg                           n! = product {p(i)^m(i)}, for i = 1, imax,
cg
cg                         where the p(i) are all of the prime numbers less than
cg                         or equal to n, and the m(i) are the exponents
cg
cg                           m(i) = sum {int (p(imax) / p(i)^k)},
cg                           for k = 1, kmax > log (p(n)) / log (p(i)).
cg
cg                         where int (x) is the largest integer <= x, and kmax
cg                         is just sufficient to make the last term zero.
cg                         An upper bound on m(p(i)) is p(imax) / (p(i) - 1).
cg                         Note that in the sum, each term after the first is
cg                         equal to the preceding term divided by p(i).
cg
cg                         For example:
cg
cg                         13!  = 1*2*3*4*5*6*7*8*9*10*11*12*13 = 6227020800
cg
cg                         m(1) = int(13/1) + int(13/1) + ...
cg                              = infinity, but 1^infinity = 1, so no matter.
cg                         m(2) = int(13/2) + int(13/4) + int(13/8) + int(13/16)
cg                              = 6 + 3 + 1 + 0 = 10
cg                         m(3) = int(13/3) + int(13/9) + int(13/27)
cg                              = 4 + 1 + 0 = 5
cg                         m(5) = int (13/5) + int(13/25) = 2 + 0 = 2
cg                         m(7) = m(11) = m(13) = 1
cg
cg                         13!  = 2^10 * 3^5 * 5^2 * 7 * 11 * 13 = 6227020800
cg
cg                         In another example, 37! ~= 1.376375309122634E43,
cg                         the powers of 2, 3, 5, 7, 11, 13 and 17 are 34, 17,
cg                         8, 5, 3, 2, and 2, respectively, and the remaining
cg                         powers of 19, 23, 29, 31, and 37 are all 1.
cg
cg                         This method is implemented for factorials up to
cg                         1012! by using macro file factf.mac in directory
cg                         ~/work/geom/test .  See test problem factf.mac.test
cg                         and output file factf.mac.hsp.

cg    factors            Selected metric conversion factors volume are in macro
cg                         file conv.mac in directory ~edwards/work/geom/test .
cg                         See "prime factors".

cc    FADD               An additive constant used to create a family of
cc                         variables with command "variable", option "series".
cc                         The floating point value var(n) of each variable is
cc                         generated from the preceding value var(n-1) by the
cc                         recursion relation:
cc
cc                         var(n) = FADD + FMULT * var(n-1), n = 2, NUMVAR + 1,
cc
cc                         where var(1) is the value of variable VAR(1).

cc    fam                A synonym for family.

cc    family             An option in command "zone", to create a family of
cc                         zones bounded by from one to three specified families
cc                         of quadric surfaces.
cc                         Synonyms:  [family, fam].
cc
cc                         This command option can be replaced, using a do loop.
cc                         See "do loop use", commands "do", "enddo".

cg    family             A family is a group of objects of the same type,
cg                         sharing some characteristic, such as being parallel,
cg                         concentric, rotated, nested, coincident, congruent,
cg                         collinear, coplanar, etc.  See "family of objects".
cg
cg                         One particular type of family of quadric surfaces
cg                         has an implicit equation F(x,y,z) = C, where C is an
cg                         arbitrary constant, different for each member of the
cg                         family.  Sometimes the family member for which C = 0
cg                         is a different type of quadric surface than the other
cg                         members of the family, e.g., coincident planes
cg                         instead of parallel planes, intersecting planes
cg                         instead of hyperbolic cylinders, and cones instead of
cg                         hyperboloids.  Also, changing C may change a
cg                         hyperboloid of one sheet to a hyperboloid of two
cg                         sheets or vice versa.

cg    family             See "family of objects".

cg    family of objects
cg                       Some commands allow a family of objects to be created
cg                         with a single command.  The object names are
cg                         generated by incrementing the preceding object name
cg                         by a specified number of characters or digits,
cg                         starting with an initial object name.
cg                         The objects are created by transforming the preceding
cg                         object in a specified way, starting from an initial
cg                         object, which itself is not part of the family.
cg                         See "increment names".
cg
cg                         See the following commands and options:
cg
cg                         COMMAND      OPTIONS
cg
cg                         variable     series
cg                         vector       rotate, scale
cg
cg                         point        rotate, scale, move, polygon,
cg                                      polyhedron, brick
cg                         triangle     increment
cg
cg                         axisym       rotate, scale, move
cg                         cone         rotate, scale, move, nest
cg                         cylinder     rotate, scale, move, concentric
cg                         ellipsoid    rotate, scale, move
cg                         hyperb       rotate, scale, move
cg                         plane        rotate, scale, move, parallel
cg                         quadric      rotate, scale, move
cg                         sphere       rotate, scale, move, concentric
cg
cg                         brick        increment
cg                         tetrahedron  increment
cg                         zone         increment, family

cg    fan                To create a family of planes at equally spaced angles
cg                         around a common axis, use command "plane" with
cg                         option "rotate".

cg    farthest           See "maximum", "distal".

cg    fatal              See commands "undo", "redo", "indo".
cg                         See "error control", "fatal error".

cg    fatal error        See commands "undo", "redo", "indo".
cg                         See "error control".

cg    Fibonacci          See "Fibonacci series".

cg    Fibonacci series   To find the Fibonacci series for any two initial
cg                         integers, use input file fib.mac.  The series ends
cg                         when the ratio of the last two terms converges.

cg    field              See "argument", "delimited", "delimiter",
cg                         "field delimiter", "field width", "vector field".

cg    field delimiter    See "delimiter".

cg    field width        To find the minimum field width for output of floating
cg                         point numbers, see "format".

cg    figures            See "significant figures".

cg    filament           A filament is a single continuous curve in 3-D space,
cg                         either bounded, as in a brick with zero thickness in
cg                         two of the three coordinate directions, or unbounded,
cg                         as in a track.

cg    file               See "files", "i/o", "input file", "output file".

cg    files              The command to execute GEOM is as follows:
cg
cg                         geom [INFILE [OUTFILE]]
cg
cg                         If an input file INFILE is not specified on the
cg                         execution line, the initial input medium is the
cg                         user's terminal.
cg
cg                         You may change the input to a file, or back to the
cg                         user's terminal, at any time, with command "input"
cg                         or "return".  Options allow you to specify the line
cg                         numbers or the initial delimited character strings of
cg                         the first and last lines to be read, and to specify
cg                         that the contents of the input file only be
cg                         displayed, and not executed as commands.
cg
cg                         If an output file OUTFILE is not specified on the
cg                         execution line, the initial output file is
cg                         "geom_hsp".
cg
cg                         You may change the current output file at any time
cg                         with command "output".
cg                         All output sent to the current output file is also
cg                         sent to the user's terminal (usually too fast to
cg                         read, if input is from a file).
cg                         All non-null input lines typed by the user, or read
cg                         from the current input file, are printed in the
cg                         current output file, prefixed by the character ">"
cg                         or "<".  This allows the output file(s) to be easily
cg                         edited into a new input file. See "input".
cg
cg                         A command summary file, "geom.cmd" is printed fore
cg                         each run, and contains all input lines, with aliases
cg                         expanded, except for commands "call", "i", "in",
cg                         "indo", "input", "r", "rd", "read", "redo", "return",
cg                         "rtn", "u" or "undo, which are not needed to produce
cg                         the same output as the original run.
cg
cg                         The files and directories associated with the GEOM
cg                         code are summarized in the file "geom_summ", and
cg                         described in the file "geom_files".

cg    files              See file geom_files in ~edwards/work/geom/doc .

cg    final              See "value".

cg    final value        See "value".

cc    find               A synonym for search.

cg    find               Find means search for in a list, or calculate or
cg                         determine by some other means.
cg                         See commands "dot", "cross", "root", "roots",
cg                         "distance", "intersect", "intcirc", "proximal",
cg                         "track", "side", "where", "area", "volume", "slice",
cg                         "extrema".
cg                         Also see command "list", and all commands that have
cg                         "list" as an option.

cg    first              See "first character".

cg    first character    The first character of any variable name must be a
cg                         lower or upper case letter or "$", "%" or "@".
cg                         When a variable name is used in place of an integer
cg                         of floating point argument, the first character may
cg                         be "-" to indicate use of the negative of the actual
cg                         variable value, but the "-" is removed to obtain the
cg                         actual variable name.  See "arguments", "VARNAME".

cc    fit                An option in command "accelerate", to fit a parabolic
cc                         trajectory to the path of a uniformly accelerated
cc                         particle, given one, two or three points on the path
cc                         at one, two or three times.
cc                         If the initial position, the initial speed (but not
cc                         its vector components), the constant acceleration,
cc                         and a second point on the parabolic trajectory are
cc                         known, use command "accelerate", option "point",
cc                         with any initial velocity vector with the same
cc                         magnitude, to find the vector components of any
cc                         initial velocities that will make the path intersect
cc                         the second point.  None, 1 or 2 may be possible.

cc    fit                An option in commands "axisym", "cone", "cylinder",
cc                         "disk", "ellipsoid", "plane", "polygon",
cc                         "polyhedron", "quadric", "sphere" and "hyperb",
cc                         between the object name and the specification of the
cc                         object.  Usually means to fit the object to the
cc                         specified points and/or axis, etc.

cg    fit                A circle may be fitted to three points.  See "circle".
cg                         A sphere may be fitted to two points, with the
cg                         center on a specified axis.  See "sphere".
cg                         A sphere may be fitted to four points.  See "sphere".
cg                         A circular ellipsoid (an oblate or prolate spheroid)
cg                         may be fitted to two points, if the center and axial
cg                         direction are specified.
cg                         See "ellipsoid".
cg                         An axially symmetric quadric surface may be fitted
cg                         to two points, if the center and axial direction are
cg                         specified.
cg                         See "axisym".
cg                         A linear trajectory may be fitted to two points
cg                         at two times.  See command "accelerate".
cg                         A parabolic trajectory may be fitted to three points
cg                         at three times.  See command "accelerate".

cg    FLAG               Indicates type of entry in geom_base:
cg                         cc     Command
cg                         cd     Directory name.
cg                         cf     Function.
cg                         cg     General information.
cg                         cn     File name.
cg                         cpar   Code parameter.
cg                         cx     Executable file.

cg    flags              See commands "alias", "marker".

cg    flip               See "flip a coin".

cg    flip a coin        To randomly choose between two events:
cg
cg                         To spin the random number sequence first:
cg
cg                         spin random
cg
cg                           Set the random number seed to a new value based on
cg                           the date and clock.  This will make any results
cg                           based on random numbers not reproducible.
cg
cg                         spin N
cg
cg                           Use up the next N random numbers.
cg
cg                         icalc 1 ran 2
cg
cg                           Randomly sample one of the integers 1 and 2.

cg    floating           See "floating point".

cg    floating point     A decimal floating point argument is a delimited
cg                         character string consisting of a plus (optional) or
cg                         minus sign, followed by a mantissa consisting only
cg                         of one or more of the numerals 0-9, and (optionally)
cg                         a decimal point (in any order), followed (optionally)
cg                         by an exponent consisting (optionally) by D, d, E or
cg                         e, followed by a plus (optional) or minus sign,
cg                         followed by one or more of the numerals 0-9.  If
cg                         neither a decimal point or an exponent is present,
cg                         the string may also be interpreted as an integer.
cg                         Any number of meaningless zeroes may precede the
cg                         leftmost nonzero digit of the mantissa, to the left
cg                         of any decimal point or sign.
cg                         Any number of meaningless zeroes may precede the
cg                         leftmost nonzero digit of the exponent.
cg                         On the YANA machines, using 64 bit floating point
cg                         numbers, the mantissa may have a precision of about
cg                         1 part in 10^16 (53 bits).  Exponents may range from
cg                         about -308 to 308.
cg
cg                         Any decimal floating point argument in a command may
cg                         be replaced by an integer or floating point variable,
cg                         or by a symbolic word which, after symbol
cg                         replacement, is an integer or floating point value.
cg
cg                         Before any command is executed, all floating point
cg                         variables used for floating point arguments are
cg                         replaced by their floating point values.
cg
cg                         See "compress", "integer", "significant figures",
cg                         command "hex".

cc    FMULT              In command "variable", option "series", a multiplier
cc                         used to create a series of variables.
cc                         Each variable var(n) is generated from the preceding
cc                         variable var(n-1) by the recursion relation:
cc
cc                         var(n) = FADD + FMULT * var(n-1), n = 2, NUMVAR + 1,
cc
cc                         where var(1) is the value of variable VAR(1).
cc                         May be integer, floating point or an integer or
cc                         floating point variable.

cc    FMULT              In command "brick", option "x", "y", "z", "rcyl",
cc                         "theta", "rsph" or "phi", a multiplier used to create
cc                         a family of bricks.  The ratio of the thickness of
cc                         each brick in the family to that of the preceding
cc                         brick is FMULT, which must be positive.  May be
cc                         integer, floating point or a variable.

cc    foc                A synonym for focus.

cc    focal              A synonym for focus.

cg    focal              See "focus".

cg    focal point        See "focus".

cg    foci               See "focus".

cg    focus              A quadric surface may have one or more foci, or focal
cg                         points, if one of the types:
cg                         parabolic cylinder, hyperbolic cylinder,
cg                         elliptic cylinder, hyperbolic paraboloid,
cg                         elliptic paraboloid, circular paraboloid, or
cg                         ellipsoid.  See a math or geometry handbook for
cg                         definitions and equations.  For a circular cone,
cg                         the focal point is at the vertex.
cg
cg                         For the parabola or parabolic cylinder:
cg                         QY * y + QXX * x^2 = 0, for all z,
cg                         the focus is at x = 0, y = -0.25 * QY / QXX.
cg
cg                         For the parabola or parabolic cylinder:
cg                         QZ * z + QXX * x^2 = 0, for all y,
cg                         the focus is at x = 0, z = -0.25 * QZ / QXX.
cg
cg                         For the hyperbola or hyperbolic cylinder:
cg                         QC + QXX * x^2 + QYY * y^2 = 0, for all z,
cg                         (QXX > 0, QYY < 0), the two foci are at
cg                         x = 0, y = (+/-)sqrt (QC / QXX - QC / QYY), (QC > 0),
cg                         y = 0, x = (+/-)sqrt (QC / QYY - QC / QXX), (QC < 0).
cg
cg                         For the ellipse or elliptic cylinder:
cg                         QC + QXX * x^2 + QYY * y^2 = 0, for all z,
cg                         (QC < 0, QXX => QYY > 0), the two foci are at:
cg                         x = 0, y = (+/-)sqrt (QC / QXX - QC / QYY).
cg
cg                         For the circular or elliptic paraboloid:
cg                         QZ * z + QXX * x^2 + QYY * y^2 = 0,
cg                         (QXX => QYY => 0), the focus is at x = y = 0,
cg                         z = -0.25 * QZ / QYY, in plane x = 0, and
cg                         z = -0.25 * QZ / QXX, in plane y = 0.
cg
cg                         For the hyperboloid of one sheet:
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QC < 0, QXX => QYY > 0, QZZ < 0),
cg                         the two foci are at z = 0,
cg                         y = (+/-)sqrt (QC / QZZ - QC / QYY), in plane x = 0,
cg                         x = (+/-)sqrt (QC / QZZ - QC / QXX), in plane y = 0.
cg
cg                         For the hyperboloid of two sheets:
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QC > 0, QXX => QYY > 0, QZZ < 0),
cg                         the two foci are at x = y = 0,
cg                         z = (+/-)sqrt (QC / QYY - QC / QZZ), in plane x = 0,
cg                         z = (+/-)sqrt (QC / QXX - QC / QZZ), in plane y = 0.
cg
cg                         For the ellipsoid:
cg                         QC + QXX * x^2 + QYY * y^2 + QZZ * z^2 = 0,
cg                         (QC < 0, QXX => QYY => QZZ => 0),
cg                         the two foci are at:
cg                         z = (+/-)sqrt (QC / QYY - QC / QZZ), in plane x = 0,
cg                         z = (+/-)sqrt (QC / QXX - QC / QZZ), in plane y = 0,
cg                         y = (+/-)sqrt (QC / QXX - QC / QYY), in plane z = 0.

cc    focus              An option in command "axisym", to fit an axially
cc                          symmetric quadric surface to a specified focal point
cc                          and axis, given two points in the surface.
cc                         Synonyms:  [focus, foc, focal].

cg    form               See "command form".

cg    format             The format to use for output of a floating point
cg                         number, to minimize the space required for a given
cg                         number of significant figures, is AB.C, which may be
cg                         found from:
cg
cg                         x = the value of the floating point number.
cg                         E = exponent of x = int (log10 (abs (x))).
cg                         N = the number of significant figures in output.
cg                         K = 0 for positive x, 1 for negative x.
cg
cg                         E            A     B               C
cg                         ---------    ---   -------------   ---------
cg                         < -3         1pe   N + 6 + K       N - 1
cg                         -3 to 0      f     N + 2 + K - E   N - 1 - E
cg                         0 to N - 1   f     N + 2 + K       N - 1 - E
cg                         N to N + 2   f         3 + K + E   0
cg                         > N + 2      1pe   N + 6 + K       N - 1
cg
cg                         After the output is produced, further reductions may
cg                         be obtained by editing the output file with UNIX text
cg                         editor VI as follows:
cg
cg                         command        purpose
cg                         ------------   --------------------------------------
cg                         :%s/00*E/E/g   eliminate trailing zeros in mantissa
cg                         :%s/E+00//g    eliminate zero exponent
cg                         :%s/E+0*/+/g   minimize characters in positive
cg                                        exponent
cg                         :%s/E-0*/-/g   minimize characters in negative
cg                                        exponent
cg                         :%s/\.\>//g    eliminate final decimal point of
cg                                        integer
cg                         :%s/  */ /g    eliminate multiple blank spaces
cg                         :%s.  *$//g    eliminate trailing blanks at end of
cg                                        line

cg    fraction           See "continued fraction", "fractional dist",
cg                         "rational fraction".

cg    fractional         See "fractional dist".

cg    fractional dist    A useful measure of the local coordinates of a point is
cg                         often the fractional distance from the beginning to
cg                         the end of a line, or the fractional distance from
cg                         one edge of a polygon to an opposite edge, or the
cg                         fractional distance from one face of a polyhedron to
cg                         an opposite face.
cg                         Used in GEOM for bricks, in the sense of dividing
cg                         the brick into fractional volumes.
cg                         See "local coordinates", "vertex weights".

cg    frequency          To randomly sample photon frequencies or energies from
cg                         a Planck spectrum or a Wien spectrum:
cg
cg                         bin BINAME [planck,wien] BTEMP
cg
cg                           Create probability bin BINAME with relative total
cg                           probability PRTOT, with a probability distribution
cg                           of a [Planck, Wien] spectrum at temperature BTEMP.
cg                           The random variable is a frequency XNU (same units
cg                           as BTEMP) from that spectrum, ranging from 0 to
cg                           infinity.  See "Planck spectrum", "Wien spectrum".
cg                           1 K (Kelvin) = 8.617385E-5 eV (+/- 8.5 ppm).
cg
cg                         pdf PDFNAME = BINAME
cg
cg                           Create new pdf PDFNAME, consisting only of the
cg                           probability bin BINAME.
cg
cg                         sample PDFNAME [NSAMP|1]
cg
cg                           Randomly sample from probability distribution
cg                           function (pdf) PDFNAME, to obtain NSAMP values of
cg                           XNU.  If specified, NSAMP must be a positive
cg                           integer or integer variable.  Only the first 26
cg                           samples will be displayed on the user's
cg                           terminal.  All will be displayed in the current
cg                           output file.  If two or more values are sampled,
cg                           the total, the minimum and maximum, the mean and
cg                           the standard deviation are displayed.

cg    frequency          See "frequency ratios".

cg    frequency ratios   For the frequency ratios of an equally-tempered musical
cg                         scale, see "equally-tempered", "scale.mac".

cg    FU                 See "FU, FV, FW".

cc    FU, FV, FW         Fractional distances (on a volume basis) of a point
cc                         between the minimum and maximum coordinates of a
cc                         brick, in the u, v and w coordinate directions,
cc                         which may be (x, y, z), (rcyl, theta, z) or
cc                         (rsph, theta, phi), based on the coordinate system
cc                         used to create the brick.  For example, the centroid
cc                         of a brick is at FU = 0.5, FV = 0.5, FW = 0.5.
cc                         Used in command "point'.

cc    FUNCTION           In command "icalc", indicates a type of mathematical
cc                         operation to be carried out, with two integer
cc                         arguments, in format "M FUNCTION N":.
cc
cc                         FUNCTION | value
cc                         ---------|--------------------------------------
cc                         +        | M + N
cc                         -        | M - N
cc                         *        | M * N
cc                         /        | M / N        (N nonzero)
cc                         ^        | M^N          (N > -1)
cc                         fact     | M * N!       (-1 < N < 20)
cc                         abs      | M * iabs(N)
cc                         ---------|--------------------------------------
cc                         max      | max0  (M, N)
cc                         min      | min0  (M, N)
cc                         mod      | mod   (M, N) (N nonzero)
cc                         sign     | isign (M, N)
cc                         ---------|--------------------------------------
cc                         comp.    | Boolean complement
cc                         .not.    | Boolean not
cc                         .and.    | Boolean intersection
cc                         .nand.   | Boolean nonintersection
cc                         .or.     | Boolean union
cc                         .nor.    | Boolean nor
cc                         .xor.    | Boolean exclusive or
cc                         .xnor.   | Boolean equivalence
cc                         ---------|--------------------------------------
cc                         perm     | M perm N     (permutations, P(M,N))
cc                         comb     | M comb N     (combinations, C(M,N))
cc                         ------------------------------------------------
cc
cc                         Synonyms:  [^, **], [.and., .int.], [.or., .un.]
cc                         [.xnor., .eqv.].

cc    FUNCTION           In command "variable", indicates a type of mathematical
cc                         operation to be carried out, with two numerical
cc                         arguments, which may be integer or floating point
cc                         values, variables, or symbolic words which, after
cc                         symbol replacement, are integer or floating point,
cc                         in format "A FUNCTION B":
cc
cc                         FUNCTION | value           || FUNCTION | value
cc                         ---------|-----------------||----------|-------------
cc                         +        | A + B           || *        | A * B
cc                         -        | A - B           || /        | A / B
cc                         ^        | A^B             || exp      | A*exp(B)
cc                         sqrt     | A*sqrt(B)       || curt     | A*B^(1/3)
cc                         log      | A*log(B)        || log10    | A*log10(B)
cc                         sin      | A*sin(B)        || asin     | A*asin(B)
cc                         cos      | A*cos(B)        || acos     | A*acos(B)
cc                         tangent  | A*tan(B)        || atan     | A*atan(B)
cc                         atan2    | atan2(A,B)      ||
cc                         sinh     | A*sinh(B)       || asinh    | A*atanh(B)
cc                         cosh     | A*cosh(B)       || acosh    | A*acosh(B)
cc                         tanh     | A*tanh(B)       || atanh    | A*atanh(B)
cc                         abs      | A*abs(B)        || sign     | sign(A,B)
cc                         int      | A*aint(B)       || nint     | A*nint(B)
cc                         max      | amax1(A,B)      || min      | amin1(A,B)
cc                         mod      | amod(A,B)       ||          |
cc                         ran      | a random number ||          |
cc                                  | between A and B ||          |
cc                         -----------------------------------------------------
cc
cc                         Synonyms:  [^, **], [tangent, tan].

cg    function           To do simple mathematics, including the use of in-line
cg                         FORTRAN functions, use command "icalc" or "variable".
cg                         See command "math".

cg    function           See "Totient function", "totient function",
cg                         "zeta function".

cg    FV                 See "FU, FV, FW".

cc    FVAR               The numerical value of a floating point variable
cc                         specified with command "variable".  If FVAR is within
cc                         fraction TOL of an integer, the variable will be an
cc                         integer variable.  FVAR itself may be numerical, the
cc                         name of an integer or floating point variable, or a
cc                         symbolic word which, after symbol replacement, is
cc                         integer or floating point.  See "AVAR", "IVAR".

cg    FW                 See "FU, FV, FW".

G-------------------------------------------------------------------------------

cg    games              Command files allowing several games to be played are
cg                        in directory ~/work/geom/test .  These files contain
cg                        instructions on how to use them, and include:
cg
cg                        card.mac       Deals from a deck of cards.
cg                        dice.mac       Rolls dice.
cg                        tictactoe.mac  Plays tic-tac-toe.

cg    GAMMA              The random variable in a relativistic Maxwellian
cg                         probability distribution function is BETA, the ratio
cg                         of the particle velocity, v, to the velocity of
cg                         light, c = 299,792,458 m / s.
cg                         A related variable is the relativistic function
cg                         GAMMA = 1 / sqrt (1 - BETA^2).
cg                         For RATIO << 1, where RATIO is the dimensionless
cg                         ratio of gas temperature to particle rest mass
cg                         energy, the expected value of BETA is approximately
cg                         1.60 * sqrt (RATIO), with a standard deviation of
cg                         approximately 0.67 * sqrt (RATIO), and the expected
cg                         value of BETA^2 is 3 * RATIO.
cg                         For RATIO >> 1, the expected value of BETA is
cg                         approximately 1 - 0.23 / RATIO^2, with a standard
cg                         deviation of approximately 1.26 / RATIO^2,
cg                         the expected value of BETA^2 is approximately
cg                         1 - 0.46 / RATIO^2, the expected value of GAMMA is
cg                         3 * RATIO, with a standard deviation of approximately
cg                         1.73 * RATIO, and the expected value of GAMMA^2 is
cg                         12 * RATIO^2.

cc    gcd                An option in commands "icalc" and "variable", to find
cc                         the greatest common divisor of a pair of numbers.
cc                         For more than two numbers, repeat the command with
cc                         the result and the next number.
cc                         See "common divisor".

cg    GEOM               The code name used in the output file.

cd    geom               Directory for GEOM files.
cd                         Open YANA Cluster:  ~edwards/geom
cd                         Subdirectories:  doc, make, test

cg    geom               See "GEOM execution".

cx    GEOM execution     Execution line command to run GEOM, the code,
cx                         application or executable program described in this
cx                         database.  Although printed as "GEOM" in this
cx                         database, use lower case "geom" to execute.
cx
cx                         In Open YANA Cluster:  ~edwards/work/bin/geom
cx
cx                         Forms include:
cx
cxin                       geom
cxin                       geom tty
cxin                       geom IN_FILE
cxin                       geom IN_FILE geom_hsp
cxin                       geom IN_FILE OUT_FILE
cxin                       geom IN_FILE OUT_FILE > STDOUT
cx
cx                           Execute the GEOM code.  If the input file tty or
cx                           IN_FILE is not specified, it defaults to tty,
cx                           indicating the user's terminal.
cx                           File IN_FILE must not be geom_hsp or geom_cmd, and
cx                           if not tty, it's first line should be command
cx                           "title".
cx
cx                           If IN_FILE is specified, and the output file
cx                           geom_hsp or OUT_FILE is not specified, it defaults
cx                           to geom_hsp.
cx                           File OUT_FILE must not be tty or geom_cmd.
cx
cx                           If the standard output STDOUT is not specified, it
cx                           defaults to the users terminal.  File STDOUT may be
cx                           specified to prevent large amounts of data from
cx                           being displayed on the user's terminal.
cx                           File STDOUT must not be tty, geom_hsp or geom_cmd.
cx
cx                           The various possibilities are described below.
cx
cx                         geom
cx                         geom tty
cx                         geom tty geom_hsp
cx
cx                           Execute the GEOM code, with input from the user's
cx                           terminal, and output to file geom_hsp and to the
cx                           user's terminal, and a command summary to file
cx                           geom_cmd.
cx
cx                           If executing GEOM for the first time, after
cx                           (optionally) specifying the problem title, type
cx                           command "help", then any other desired commands.
cx
cx                         geom IN_FILE
cx                         geom IN_FILE geom_hsp
cx
cx                           Execute the GEOM code, with input from file
cx                           IN_FILE, and output to file geom_hsp and to the
cx                           user's terminal, and a command summary to file
cx                           geom_cmd.
cx
cx                         geom IN_FILE OUT_FILE
cx
cx                           Execute the GEOM code, with input from file
cx                           IN_FILE, and output to file OUT_FILE and to the
cx                           user's terminal, and a command summary to file
cx                           geom_cmd.
cx
cx                         geom IN_FILE OUT_FILE > STDOUT
cx
cx                           Execute the GEOM code, with input from file
cx                           IN_FILE, and output to file OUT_FILE and to file
cx                           STDOUT, and a command summary to file geom_cmd.
cx
cx                         NOTE:  Do NOT use the UNIX execution line symbol
cx                         "<" to redirect the standard input.  You may use
cx                         the UNIX execution line symbol ">" to redirect the
cx                         standard output.  Use ">!" to write over an existing
cx                         file STDOUT.
cx
cx                         NOTE:  input will return to the user's terminal after
cx                         the last line of file IN_FILE, unless GEOM first
cx                         executes command "input", "return" or "end".
cx                         See commands "if", "endif".

cg    geometric          To display, create and use geometric objects, see the
cg                         entries and commands:  point, cluster, mesh, line,
cg                         triangle, polygon, disk, plane, sphere, cylinder,
cg                         cone, ellipsoid, axisym, quadric, polyhedron,
cg                         tetrahedron, brick, zone.

cg    geometric          See "geometric series".

cg    geometric optics   See "ray tracing".

cg    geometric series   A geometric series is one in which the value of each
cg                         term after the first term differs from the preceding
cg                         term by a constant ratio.  See command "ratio".
cg                         To create a family of variables whose values form a
cg                         geometric series:
cg
cg                         variable VAR(1) = VALUE
cg
cg                           Create variable VAR(1), with the value of the first
cg                           term.
cg
cg                         variable VAR(2) series NUMVAR INC VAR(1) 0 FMULT
cg
cg                           Create a series of NUMVAR variables VAR(2), ...,
cg                           with names incremented by INC characters, with each
cg                           value equal to the preceding value multiplied by
cg                           FADD, starting from the value of variable VAR(1).
cg                           See "increment names".
cg
cg                         To create a family of points, planes or quadric
cg                         surfaces in which the distance of each from an
cg                         invariant point, axis or plane forms a geometric
cg                         series, use option "scale" of command "point",
cg                         "plane", "sphere", "cylinder", "cone", "ellipsoid",
cg                         "axisym" or "quadric".

cn    geom_APT           A list of all APT subroutines, with use by the GEOM
cn                         code indicated.  See "calls", "map".

cn    geom_APT.not       A list of APT subroutines not used by GEOM.

cn    geom_base          This file.  Database of commands, key words, and all
cn                         related terminology in GEOM.
cn                         Long name:  ~edwards/work/geom/doc/geom_base
cn
cn                         In Open YANA Cluster:  ~edwards/work/geom/doc
cn
cn                         To display entries while executing GEOM, see
cn                         command "display".

cn    geom_cmd           A file containing all of the input commands needed to
cn                         reproduce the output produced by the current problem,
cn                         with aliases expanded, and with commands "call",
cn                         "goto", "i", "in", "indo", "input", "r", "rd",
cn                         "read", "redo", "return", "rtn", "u" and "undo
cn                         converted to comments, preceded by "! ".
cn                         The latter commands are preceded by the character
cn                         "<" in the current output file, initially geom_hsp.
cn
cn                         May not be specified as an input file on the
cn                         execution line, e.g. "geom geom_cmd" will not work.
cn
cn                         May be used as an input file after execution, using
cn                         command "input", but limited to the input commands
cn                         already written into it.

cn    geom_commands      A list of all GEOM commands, with a brief description
cn                         of their function.
cn                         Long name:  ~edwards/work/geom/doc/geom_commands

cn    geom_define        A list of all of the entries in this file, without
cn                         definitions.

cn    geom_diff.all      An executable script to compare old and new GEOM test
cn                         problem output files, after running geom_mv.hsp.all
cn                         and geom_exe.all.

cn    geom_exe.all       An executable script to run all GEOM test problems,
cn                         after running geom_mv.hsp.all, and before running
cn                         geom_diff.all.

cn    geom_files         A summary of all subroutines and files associated with
cn                         the GEOM code.
cn                         Long name:  ~edwards/work/geom/doc/geom_files

cn    geom_head          A summary of the header sections from all GEOM
cn                         subroutines
cn                         Long name:  ~edwards/work/geom/doc/geom_head

cn    geom_head.make     A file used to create file geom_head.
cn                         Long name:  ~edwards/work/geom/doc/geom_head.make

cn    geom_hsp           The initial output file of problem results.
cn                         See "output file", "geom_cmd".
cn                         Do not specify as the input file on the GEOM
cn                         execution line, e.g., "geom geom_hsp", or during a
cn                         GEOM run, unless the current output file is not
cn                         geom_hsp, and then only to display lines or execute
cn                         lines that have the form of commands.

cn    geom_input         A list of all GEOM code command lines, including all
cn                         options.
cn                         Long name:  ~edwards/work/geom/doc/geom_input

cn    geom_internal      A list of all GEOM internal parameters and variables in
cn                         file store.h, alphabetic and by data groups, with
cn                         definitions.  See command "debug".

cn    geom_log           A log of the development, modifications and maintenance
cn                         of the GEOM code.
cn                         Long name:  ~edwards/work/geom/doc/geom_log

cn    geom_make          A summary of procedures to maintain and update the
cn                         GEOM code, and add new subroutines.
cn                         Long name:  ~edwards/work/geom/make/geom_make

cn    geom_mv.hsp.all    An executable script to rename all GEOM test problem
cn                         output files, by appending the suffix ".old",
cn                         before running geom_exe.all and geom_diff.all.

cn    geom_summ          A summary of the names and locations of the GEOM code
cn                         files.
cn                         Long name:  ~edwards/work/geom/doc/geom_summ

cn    geom_tests         A summary of all command lines in GEOM test files.
cn                         Long name:  ~edwards/work/geom/doc/geom_tests

cg    getting started    See "starting up".

cc    go to              See command "goto".

cg    golden             See "golden ratio".

cg    golden ratio       The "golden ratio" 0.5 * (1.0 + sqrt (5.0)) or
cg                         1.618033988749894848204586834365638117720309189
cg                         Generated as a variable at the beginning of a
cg                         GEOM run.  The roots of x^2 - x - 1 = 0 are
cg                         rgold and 1 - rgold.  Also rgold = 1 + 1 / rgold.
cc                         Store as a big integer with command "input big.mac",
cc                         with file big.mac in the same directory as GEOM.

cc    goto               Command to jump to a new command in the current input
cc                         file, rather than the next command in sequence.
cc                         See command "input".
cc
cc                         Command "goto" relates to objects:  symbol, variable.
cc
cc                         Note:  do not use a "goto" command when input is from
cc                         the user's terminal.
cc
cc                         Note:  do not use a "goto" command to jump into or
cc                         out of a do loop.
cc
cc                         Note:  Do not use the statement separator ";" on the
cc                         same line as this command.
cc
cc                         Forms include:
cc
ccin                       help goto
ccin                       goto [help]
cc
cc                           Display the command options.
cc
ccin                       goto STRING1
cc
cc                           Read the current input file, from the first line
cc                           starting with STRING1 to the end of the file,
cc