eqn(1BSD) (BSD System Compatibility) eqn(1BSD)
NAME
eqn, neqn, checkeq - (BSD) typeset mathematics
SYNOPSIS
/usr/ucb/eqn [-dxy] [-fn] [-pn] [-sn] [file] . . .
/usr/ucb/neqn [file] . . .
/usr/ucb/checkeq [file] . . .
DESCRIPTION
The eqn and neqn commands are language processors to assist in
describing equations. eqn is a preprocessor for troff(1BSD)
and is intended for devices that can print troff's output.
neqn is a preprocessor for nroff(1BSD) and is intended for use
with terminals.
checkeq reports missing or unbalanced delimiters and .EQ/.EN
pairs.
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.
The following options are available for eqn and neqn:
-dxy Set 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 Change font to n globally in the document. The font can
also be changed globally in the body of the document by
using the gfont directive.
-pn Reduce subscripts and superscripts by n point sizes from
the prevailing size. In the absence of the -p option,
subscripts and superscripts are reduced by 3 point sizes
from the prevailing size.
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eqn(1BSD) (BSD System Compatibility) eqn(1BSD)
-sn Set equations in point size n globally in the document.
The point size can also be changed globally in the body
of the document by using the gsize directive.
-Tdev Prepare output for device dev. If no -T option is
present, eqn looks at the environment variable
TYPESETTER to see what the intended output device is.
If no such variable is found in the environment, a
system-dependent default device is assumed. Not
available using neqn.
USAGE
eqn Language
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. Tilde
(~) represents a full space in the output, circumflex (^) half
as much.
Subscripts and superscripts are produced with the keywords sub
and sup:
x sub i: xi
e sup {x sup 2 + y sup 2}: ex2 + y2
2
a sub i sup 2: ai
Fractions are made with over:
a over b:
Square roots are made with sqrt:
1 over down 10 sqrt {ax sup 2 +bx+c}:
Although eqn tries to get most things at the right place on
the paper, occasionally you will need to tune the output to
make it just right. Local motions such as, up n, down n, fwd
n and back n allow you to change the default spacing. In the
previous example, a local motion, down 10, was used to get
more space between the square root and the line above it.
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eqn(1BSD) (BSD System Compatibility) eqn(1BSD)
Lower and upper limits are made with from and to:
lim from {n-> inf} sum from 0 to n x sub i:
Brackets and braces of the right height are made with left and
right:
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}:
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 } }:
In addition, there is rcol for a right-justified column.
Diacritical marks are made with dot, dotdot, hat, tilde, bar,
vec, dyad, and under:
x dot = f(t) bar:
y dotdot bar ~=~ n under:
x vec ~=~ y dyad:
Size and font can be changed with size n or size _n, roman,
italic, bold, and font n. Size and font can be changed
globally in a document by gsize n and gfont n, or by the
command-line arguments -sn and -fn.
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eqn(1BSD) (BSD System Compatibility) eqn(1BSD)
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 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 like sum (>), inf (oo), and shorthands like >= (>),
-> (->), and != (/) are recognized. Greek letters are spelled
out in the desired case, as in alpha or GAMMA. Mathematical
words like sin, cos, and log are made Roman automatically.
troff(1BSD) four-character escapes like \(bu (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.
EXAMPLE
eqn file . . . | troff
neqn file . . . | nroff
REFERENCES
eqnchar(5BSD), ms(5BSD), tbl(1BSD), troff(1BSD)
NOTICES
To embolden digits, parens, and so on, it is necessary to
quote them, as in bold "12.3".
Copyright 1994 Novell, Inc. Page 4