
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 pre
processor 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 begin
ning 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 commandline argu
ment. 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 xi
a sub i sup 2 produces ai
e sup {x sup 2 + y sup 2} gives e^(x^2+y^2)
Fractions:
Fractions are made with over.
a over b yields _
Square Roots:
These are made with sqrt
1 over sqrt {ax sup 2 +bx+c}
results in _________
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 nlimo>xi
0
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 [x2+__]=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 rightsideonly bracket).
Vertical piles:
Vertical piles of things are made with pile, lpile, cpile, and rpile.
a
pile {a above b above c}
produces b
c
There can be an arbitrary number of elements in a pile.
lpile leftjustifies, pile and cpile center, with differ
ent 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 } }
xi 1
produces
y2 2
In addition, there is rcol for a rightjustified 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 commandline 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) fourcharacter escapes like o (o) can be used anywhere. Strings enclosed in dou
ble 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.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+++
 ATTRIBUTE TYPE  ATTRIBUTE VALUE 
+++
Availability SUNWdoc 
+++
SEE ALSO
nroff(1), tbl(1), troff(1), attributes(5), ms(5)
BUGS
To embolden characters such as digits and parentheses, it is necessary to quote them, as
in `bold "12.3"'.
SunOS 5.11 12 Jul 2002 eqn(1) 
