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 ________
|        |
|  .SUB  |
|  .SUBD |
!        !
|________|
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.hl 1;SUB and SUBD commands
SUB/SUBD define phrases to be substituted during RUNOFF processing.
.ix String substitution/setting
.ix Phrase dictionary
.ix SUB/SUBD
.s.lm +7.nf
 _________ ___________________________________
|  .SUB   |                                   |
|    or   |    variable = "character string"  |
|  .SUBD  |                                   |
|_________|___________________________________|
.fi.lm LEFTMG.s
The SUB/SUBD commands set 'variable' to the character string on the
righthand side of the equal sign. When RUNOFF processes the input file,
every input line ^&not\& beginning with a period in column 1, will be
searched for the appearance of 'variable'. If .SUB was specified, the
character string equivalent will be substituted for ^&any\& occurence of
'variable'. If .SUBD was specified for this 'variable', only delimited
occurences will be substituted. A delimited string is one that is
distinguished by punctuation characters, blanks, tabs etc. See the example
below.
.s 2;.lm LEFTMG
Notes:
.s;.lm +7
The length of 'variable' can be at most 6 characters. The length of 'string'
can be at most 40 characters. 'variable' can be any combination of letters,
numbers, special characters etc. Lower/upper case matching are preserved.
.b
It is possible to make substitutions within substitutions, although
recursive substitution is not possible.  Usually, the most recent .SUB
command is substituted first. The following situtation can take place -
.b
.lm+7.nf
 .SUB OK = "this is the first one"
 .SUB 2nd = "This looks OK"
 2nd
.f.b
.i-7;produces -
.b
 This looks this is the first one
.lm-7.b
Since substitution does not take place for commands (lines starting with a
period), you must use the two line form of commands such as .CENTER for
substitution to work.
.b
There is currently no delete symbol command, so to delete a symbol merely
redefine 'variable' to be itself %!
.b
.i7; .SUB addres = "addres"
.b
.ix Equation mode
Use of the SUB/SUBD commands within .EQ/.EEQ blocks causes any 'variables'
defined in the block to be deleted when the .EEQ command is executed. It is
useful to set 'variables' to greek symbols within equations, but you don't
want the substitution to carry over to normal text -
.b
.lm+7
 .SUB A = "%a"      ! small alpha
.b
 .SUB L = "%L"      ! large OMEGA
.lm-7.b
You can create a phase dictionary by making a file with all of your
standard substitutions and including the file (.IN) at the beginning of
your RUNOFF file.
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__________
|        |
|  .SUB  |
|  .SUBD |
|        |
|________|
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.s 2;.lm LEFTMG
Examples:
.b.lm+7
 .sub dat = "today"
.br
 The date today is dat.
.b
.i+7;produces -
.b
 The todaye today is today.
.b
But if we use the .SUBD command -
.b
 .subd dat = "today"
.br
 The date today is dat.
.b
.i+7;we get -
.b
 The date today is today.
.B2
If you are using a Qume letter gothic print wheel, the vertical bar
character is represented by an %<esc%>Y. To make every occurence of
%| be produced as vertical bar, create a file ESCAPEY.RNO with the line
.b
 .SUB %| = "%<esc%>Y"
.b
and include this file in your main RUNOFF file.
.lm LEFTMG