NAME

eqn − format mathematical text for troff

USAGE

eqn [ −dxy ] [ −pn ] [ −sn ] [ −fn ] [ files ]

DESCRIPTION

Eqn is a troff(1) preprocessor for typesetting mathematical text on a phototypesetter.  Neqn is used for the same purpose with nroff(1) on typewriter-like terminals.  These commands are normally used in this or a similar manner:

eqn files │ troff
neqn files │ nroff

If no files are specified, eqn and neqn read from the standard input.  A line beginning with .EQ marks the start of an equation; a line beginning with .EN marks the end of an equation.  Neither of these lines is altered, so they may be defined in macro packages to get centering, numbering, etc.  It is also possible to designate two characters as delimiters .  Subsequent text between delimiters is then treated as eqn input.  The left and right delimiters may be the same character; the dollar sign is often used as such a delimiter.  Delimiters are turned off by delim off. All text that is not between delimiters or between .EQ and .EN passes through untouched. 

Checkeq reports missing or unbalanced delimiters and .EQ/.EN pairs. 

Tokens within eqn are separated by spaces, tabs, newlines, braces, double quotes, tildes, and carets.  Braces ({}) are used for grouping.  Generally speaking, anywhere a single character such as x can appear, a complicated construction enclosed in braces may be used instead.  A tilde (~) represents a full space in the output, a caret (^) half as much. 

OPTIONS

−dxy Set delimiters to characters x and y. More commonly done with delim xy between .EQ and .EN. 

−pn Change the normal reduction of three points from the previous size of subscripts and superscripts to the value of n.

−sn Change point size to the value of n. 

−fn.  Change font to the value of n.

SPECIAL KEYWORDS

The following list explains the special keywords that can be used with eqn.  In addition to these, keywords such as sum (∑)int (∫)inf (∞)and shorthands like >= (≥)−> (→),and != (≠)are recognized.  Greek letters are spelled out in the desired case, as in alpha or GAMMA Mathematical words such as sin, cos, and log are made roman automatically.  Troff(1) four-character escapes such as \(dd (‡) may 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(1) when all else fails. 

NOTES

In order to make digits, parentheses, etc., appear in boldface, you must quote them, as in bold "12.3". 

RELATED INFORMATION

checkeq(1), neqn(1), tbl(1), troff(1), eqnchar(7), ms(7).  DOMAIN/IX Text Processing Guide.