


      EQN(1)			    (DWB)			 EQN(1)



      NAME
	   eqn,	neqn, checkeq -	format mathematical text for nroff or
	   troff

      SYNTAX
	   eqn [ -dxy ]	[ -pn ]	[ -sn ]	[ -fn ]	[ files	]

	   neqn	[ -dxy ] [ -pn ] [ -sn ] [ -fn ] [ files ]

	   checkeq [ files ]

      DESCRIPTION
	   Eqn is a troff(1) preprocessor for typesetting mathematical
	   text	on a phototypesetter, while neqn is used for the same
	   purpose with	nroff on typewriter-like terminals.  Usage is
	   almost always:

		eqn files | troff
		neqn files | nroff

	   or equivalent.

	   If no files are specified (or if - is specified as the last
	   argument), these programs read the standard input.  Eqn
	   prepares output for the typesetter named in the -T option.
	   Currently, the supported device is -Taps (Autologic APS-5).

	   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 designate two	characters as
	   delimiters; subsequent text between delimiters is then
	   treated as eqn 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 the same character; the dollar sign is
	   often used as such a	delimiter.  Delimiters are turned off
	   by delim off.  All text that	is neither between delimiters
	   nor between .EQ and .EN is passed through untouched.

	   The program checkeq reports missing or unbalanced delimiters
	   and .EQ/.EN pairs.

	   Tokens within eqn are separated by spaces, tabs, new-lines,
	   braces, double quotes, tildes, and circumflexes.  Braces {}
	   are used for	grouping; generally speaking, anywhere a single
	   character such as 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.




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      EQN(1)			    (DWB)			 EQN(1)



	   Subscripts and superscripts are produced with the keywords
	   sub and sup.	 Thus x	sub j makes x ,	a sub k	sup 2 produces
	    2	      x2+y2		     j
	   ak, while e	    is made with
	   e sup {x sup	2 +_y sup 2}.Fractions are made	with over:
	   a over b yields b; sqrt makes square	ro__________
	   1 over sqrt {ax sup 2+bx+c} results in   ________ .
						  \|ax2+bx+c

	   The knywords	from and to introduce lower and	upper limits:
	    lim	Rx  is made with
	   n->oo0 i
	   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:
	   |eft	2|x sup	2 + y sup 2 over alpha right ] ~=~ 1 produces
	   |x2+__| = 1.	 Legal characters after	left and right are
	   |   A |
	   braces, brackets, bars, c and f for ceiling and floor, and
	   "" for nothing at all (useful for a right-side-only
	   bracket).  A	left thing need	not have a matching right
	   thing.

	   Vertical piles of things are	made with pile,	laile, cpile,
	   and rpile:  pile {a above b above c}	produces b.  Piles may
							 c
	   have	arbitrary numbers of elements; lpile left-justifies,
	   pile	and cpile center (but with different vertical spacing),
	   and rpile right justifies.  Matrices	are made with matrix:
	   matrix { xcol1{ x sub i above y sub 2 } ccol	{ 1 above 2 } }
		     i
	   produces y	2.  In addition, there is rcol for a right-
	   justified column.

	   Diacritical marks are made with dot,	dotdot,	hat. ____e,
	   bar,	vec, dyad, and under:  __dot = f(t) bar	is x=f(t),
				       ..
	   _ do_dot bar	~=~ n under is y  = _, and x vec ~=~ y dyad is
	   x = y.

	   Point sizes and fonts can be	changed	with size n or size _n,
	   roman, italic, bold,	and font n.  Point sizes 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
	   points 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
	   subsequent equations.


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	   Shorthands may be defined or	existing keywords redefined
	   with	define:

		define thing % replacement %

	   defines a new token called thing that will be replaced by
	   replacement whenever	it appears thereafter.	The % may be
	   any character that does not occur in	replacement.

	   Keywords such as sum	(R), int (^), inf (oo),	and shorthands
	   such	as >= (>), != (/), and -> (->) are recognized.	Greek
	   letters are spelled out in the desired case,	as in alpha
	   (A),	or GAMMA (G). Mathematical words such as sin, cos, and
	   log are made	Roman automatically.  Troff(1) four-character
	   escapes such	as \(dd	(=) may	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(1) when all else
	   fails.  Full	details	are given in the manual	cited below.

      SEE ALSO
	   mm(1), mmt(1), nroff(1), tbl(1), troff(1), eqnchar(5),
	   mm(5), mv(5).  Documenter's Workbench Text Processor
	   Reference
	   Typesetting Mathematics- User Guide by B.W. Kernighan and
	   L.L.	Cherry.

      BUGS
	   To embolden digits, parentheses, etc., it is	necessary to
	   quote them, as in bold "12.3".
	   See also BUGS under troff(1).
























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