eqn(1bsd) (BSD System Compatibility)
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.
- -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
e sup {x sup 2 + y sup 2}
a sub i sup 2
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.
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.
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
(
),
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 (
) 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.
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".
Examples
eqn file . . . | troff
neqn file . . . | nroff
30 January 1998
© 1998 The Santa Cruz Operation, Inc. All rights reserved.