neqn [ file ] ...
checkeq [ file ] ...
SUNWdoc
eqn and neqn are language processors to assist in describing equations. eqn is a preprocessor for troff(1) and is intended for devices that can print troff’s output. neqn is a preprocessor for nroff(1) and is intended for use with terminals. Usage is almost always:
example% eqn file ... | troff example% neqn file ... | nroffIf no files are specified, eqn and neqn read from the standard input. A line beginning with .EQ marks the start of an equation; the end of an equation is marked by a line beginning with .EN . Neither of these lines is altered, so they may be defined in macro packages to get centering, numbering, etc. It is also possible to set two characters as ‘‘delimiters’’; subsequent text between delimiters is also treated as eqn input.
checkeq reports missing or unbalanced delimiters and .EQ/.EN pairs.
Options
The following options are supported:
- -dxy
- Set equation delimiters set to characters x and y with the command-line argument. The more common way to do this is with delim xy between .EQ and .EN . The left and right delimiters may be identical. Delimiters are turned off by delim off appearing in the text. All text that is neither between delimiters nor between .EQ and .EN is passed through untouched.
- -fn
- Change font to n globally in the document. The font can also be changed globally in the body of the document by using the gfont n directive, where n is the font specification.
- -pn
- Reduce subscripts and superscripts by n point sizes from the previous size. In the absence of the -p option, subscripts and superscripts are reduced by 3 point sizes from the previous size.
- -sn
- Change point size to n globally in the document. The point size can also be changed globally in the body of the document by using the gsize n directive, where n is the point size.
Operands
The following operands are supported:
- file
- The nroff or troff file processed by eqn or neqn.
Eqn Language
The nroff version of this description depicts the output of neqn to the terminal screen exactly as neqn is able to display it. To see an accurate depiction of the output the printed version of this page should be viewed.Tokens within eqn are separated by braces, double quotes, tildes, circumflexes, SPACE , TAB , or NEWLINE characters. Braces {} are used for grouping; generally speaking, anywhere a single character like x could appear, a complicated construction enclosed in braces may be used instead. Tilde (~ ) represents a full SPACE in the output, circumflex (^ ) half as much.
- Subscripts and superscripts:
- These are produced with the keywords sub and sup.
- ‘x sub i’ makes $x sub i$
- ‘a sub i sup 2’ produces $a sub i sup 2$
- ‘e sup {x sup 2 + y sup 2}’ gives $e sup {x sup 2 + y sup 2}$
$lim from {n-> inf} sum from 0 to n x sub i$
(The SIGMA symbol cannot be displayed in nroff)
$left [ x sup 2 + y sup 2 over alpha right ] ~=~1$.
$pile {a above b above c}$
There can be an arbitrary number of elements in a pile. lpile left-justifies, pile and cpile center, with different vertical spacing, and rpile right justifies.
In addition, there is rcol for a right-justified column.
$x dot = f(t) bar$
$y dotdot bar ~=~ n under$
$x vec ~=~ y dyad$
troff(1)
four-character
escapes like \(bu (·) can be used anywhere. Strings enclosed in double quotes
"..." are passed through untouched; this permits keywords to be entered as
text, and can be used to communicate with troff when all else fails.