EQN(1) User Commands EQN(1)
NAME
eqn, neqn, checkeq - typeset mathematics test
SYNOPSIS
eqn [
-d xy] [
-f n] [
-p n] [
-s n] [
file]...
neqn [
file]...
checkeq [
file]...
DESCRIPTION
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 ... | 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. 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, and so on. 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 Sets 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 Changes 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 Reduces 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 Changes 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, view the printed version of this page.
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. A tilde (
~) represents a full SPACE in the output; a circumflex
(
^) half as much.
Subscripts and superscripts: These are produced with the keywords
sub and
sup.
x sub i makes
x_
i a sub i sup 2 produces
a_
i^2
e sup {x sup 2 + y sup 2} gives e^(x^2+y^2)
Fractions: Fractions are made with
over.
a over b yields
a/
b Square Roots: These are made with
sqrt 1 over sqrt {ax sup 2 +bx+c} results in 1/<sqrt>(
ax^2 +
bx +
c)
Limits: 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 makes lim_(
n -> <infinity>) <sum>_0^
n x_
i Brackets and Braces: Left and right brackets, braces, and the like, of the right height
are made with
left and
right.
left [ x sup 2 + y sup 2 over alpha right ] ~=~1 produces [
x^2 + (
y^2)/<alpha>] = 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: Vertical piles of things are made with
pile,
lpile,
cpile, and
rpile.
pile {a above b above c} produces
a b 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: Matrices are made with
matrix.
matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } } produces (
x_
i y_2) (1 2)
In addition, there is
rcol for a right-justified column.
Diacritical marks: Diacritical marks are made with
dot,
dotdot,
hat,
tilde,
bar,
vec,
dyad, and
under.
x dot = f(t) bar is
x. =
f (
t)-
y dotdot bar ~=~ n under is
y"- =
n_
x vec ~=~ y dyad is
x-> =
y<->
Sizes and Fonts: 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. Successive display arguments: 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 subsequent equations.
Shorthands: 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 whenever it appears thereafter. The
% may be any
character that does not occur in
replacement.
Keywords and Shorthands: Keywords like
sum int inf and shorthands like
>= -> and
!= are
recognized.
Greek letters: Greek letters are spelled out in the desired case, as in
alpha or
GAMMA.
Mathematical words: Mathematical words like
sin,
cos, and
log are made Roman
automatically.
troff(1) four-character escapes like +o (+o) 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.
SEE ALSO
nroff(1),
tbl(1),
troff(1),
attributes(7),
ms(7)BUGS
To embolden characters such as digits and parentheses, it is necessary
to quote them, as in `
bold "12.3"'.
July 12, 2002
EQN(1)