EQN(1) EQN(1)
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NAME
eqn, neqn, checkeq - typeset mathematics
SYNOPSIS
eqn [ -dxy ] [ -pn ] [ -sn ] [ -fn ] [ -Tdest ] [ file ] ...
neqn [ option ] ... [ file ] ...
checkeq [ file ] ...
DESCRIPTION
Eqn is a troff(1) preprocessor for typesetting mathematics
on a phototypesetter, neqn on terminals. Usage is almost
always
eqn file ... | troff
neqn file ... | nroff
If no files are specified, these programs read from the
standard input. Eqn prepares output for the typesetter
named in the -T option (Mergenthaler Linotron 202 default,
see troff(1)).
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 _eeee_qqqq_nnnn
input. Delimiters may be set to characters x and y with the
command-line argument -dxy or (more commonly) with `delim
xy' between .EQ and .EN. The left and right delimiters may
be identical. Delimiters are turned off by `delim off'.
All text that is neither between delimiters nor between .EQ
and .EN is passed 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 or circumflexes. 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, and
tab represents an ordinary troff tab character.
Subscripts and superscripts are produced with the keywords
sub and sup. Thus x sub i makes $x sub i$, a sub i sup 2
produces $a sub i sup 2$, and e sup {x sup 2 + y sup 2}
EQN(1) EQN(1)
gives $e sup {x sup 2 + y sup 2}$.
Fractions are made with over: a over b yields $a over b$.
sqrt makes square roots: 1 over sqrt {ax sup 2 +bx+c}
results in $1 over sqrt {ax sup 2 +bx+c}$ .
The keywords from and to introduce lower and upper limits on
arbitrary things: $lim from {n-> inf} sum from 0 to n x sub
i$ is made with lim from {n-> inf } 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 $left [ x sup 2 + y sup 2 over
alpha right ] ~=~1$. The right clause is optional. Legal
characters after left and right are braces, brackets, bars,
c and f for ceiling and floor, and "" for nothing at all
(useful for a right-side-only bracket).
Vertical piles of things are made with pile, lpile, cpile,
and rpile: pile {a above b above c} produces $pile {a above
b above c}$. 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.
Matrices are made with matrix: matrix { lcol { x sub i above
y sub 2 } ccol { 1 above 2 } } produces $matrix { lcol { x
sub i above y sub 2 } ccol { 1 above 2 } }$. In addition,
there is rcol for a right-justified column.
Diacritical marks are made with prime, dot, dotdot, hat,
tilde, bar, under, vec, dyad, and under: x sub 0 sup prime =
f(t) bar + g(t) under is $x sub 0 sup prime = f(t) bar +
g(t) under$, and x vec= y dyad is $x vec = y dyad$.
Sizes and font can be changed with size n or size ±n, roman,
italic, bold, and font n. Size and fonts can be changed
globally in a document by gsize n and gfont n, or by the
command-line arguments -sn and -fn.
Normally subscripts and superscripts are reduced by 3 point
sizes from the previous size; this may be changed by the
command-line argument -pn.
Successive display arguments can be lined up. Place mark
before the desired lineup point in the first equation; place
lineup at the place that is to line up vertically in subse-
quent equations.
Shorthands may be defined or existing keywords redefined
with define: define thing % replacement % defines a new
token called thing which will be replaced by replacement
EQN(1) EQN(1)
whenever it appears thereafter. The % may be any character
that does not occur in replacement.
Keywords like sum ( sum ) int ( int ) inf ( inf ) and short-
hands like >= (>=) -> (->), and != ( != ) are recognized.
Greek letters are spelled out in the desired case, as in
alpha or GAMMA. Mathematical words like sin, cos, log are
made Roman automatically. Troff(1) four-character escapes
like \(lh () can be used anywhere. Strings enclosed in
double quotes "..." are passed through untouched; this per-
mits keywords to be entered as text, and can be used to com-
municate with troff when all else fails.
SEE ALSO
troff(1), tbl(1), ms(7), eqnchar(7), doctype(1)
B. W. Kernighan and L. L. Cherry, _TTTT_yyyy_pppp_eeee_ssss_eeee_tttt_tttt_iiii_nnnn_gggg _MMMM_aaaa_tttt_hhhh_eeee_mmmm_aaaa_tttt_iiii_cccc_ssss-
_UUUU_ssss_eeee_rrrr'_ssss _GGGG_uuuu_iiii_dddd_eeee
J. F. Ossanna, _NNNN_RRRR_OOOO_FFFF_FFFF/_TTTT_RRRR_OOOO_FFFF_FFFF _UUUU_ssss_eeee_rrrr'_ssss _MMMM_aaaa_nnnn_uuuu_aaaa_llll
BUGS
To embolden digits, parens, etc., it is necessary to quote
them, as in `bold "12.3"'.