EQN(I) 2/22/74 EQN(I)
NAME
eqn - typeset mathematics
SYNOPSIS
eqn [ file ] ...
DESCRIPTION
Eqn is a troff (I) preprocessor for typesetting mathematics
on the Graphics Systems phototypesetter. Usage is almost
always
eqn file ... | troff
If no files are specified, eqn reads 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
or defined by eqn, so you can define them yourself to get
centering, numbering, etc. All other lines are treated as
comments, and passed through untouched.
Spaces, tabs, newlines, braces, double quotes, tilde and
circumflex are the only delimiters. Braces ``{}'' are used
for grouping. Use tildes ``~'' to get extra spaces in an
equation.
Subscripts and superscripts are produced with the keywords
sub and sup. Thus x sub i makes xi, a sub i sup 2 produces
2 2 2
ai, and e sup {x sup 2 + y sup 2} gives ex +y . Fractions
a
are made with over. a over b is _ and 1 over sqrt {ax sup 2
b
1
+bx+c} is ________ . sqrt makes square roots.
\/ax2+bx+c
The keywords from and to introduce lower and upper limits on
n
arbitrary things: lim Σxi is made with lim from {n-> inf}
n->oo0
sum from 0 to n x sub i. Left and right brackets, braces,
etc., of the right height are made with left and right: left
[ x sup 2 + y sup 2 over alpha right ] ~=~1 produces
| |
y2
|x2+ __| = 1. The right clause is optional.
α
| |
Vertical piles of things are made with pile, lpile, cpile,
a
and rpile: pile {a above b above c} produces b. There can
c
be an arbitrary number of elements in a pile. lpile left-
justifies, pile and cpile center, with different vertical
spacing, and rpile right justifies.
Diacritical marks are made with dot, dotdot, hat, bar: x dot
. ____
= f(t) bar is x=f(t). Default sizes and fonts can be
changed with size n and various of roman, italic, and bold.
Keywords like sum (Σ) int (∫) inf (oo) and shorthands like
>= (>) -> (->), != (≠), are recognized. Spell out Greek
letters in the desired case, as in alpha, GAMMA.
Mathematical words like sin, cos, log are made Roman
automatically. Troff (I) four-character escapes like \(bs
(o) can be used anywhere. Strings enclosed in double quotes
"..." are passed through untouched.
SEE ALSO
A System for Typesetting Mathematics (Computer Science
Technical Report #17, Bell Laboratories, 1974.)
TROFF Users' Manual (internal memorandum)
TROFF Made Trivial (internal memorandum)
troff (I), neqn (I)
BUGS
Undoubtedly. Watch out for small or large point sizes -
it's tuned too well for size 10. Be cautious if inserting
horizontal or vertical motions, and of backslashes in
general.