6 eqn \- typeset mathematics
20 for typesetting mathematics
22 Usage is almost always
27 If no files are specified,
29 reads from the standard input.
31 prepares output for the typesetter
38 When run with other preprocessor filters,
44 marks the start of an equation;
45 the end of an equation
46 is marked by a line beginning with
48 Neither of these lines is altered,
49 so they may be defined in macro packages
51 centering, numbering, etc.
52 It is also possible to set two characters
54 text between delimiters is also
57 Delimiters may be set to characters
63 or (more commonly) with
70 Left and right delimiters may be identical.
71 (They are customarily taken to be
73 Delimiters are turned off by
75 All text that is neither between delimiters nor between
79 is passed through untouched.
84 spaces, tabs, newlines, braces, double quotes,
85 tildes or circumflexes.
86 Braces {} are used for grouping;
88 anywhere a single character like
90 could appear, a complicated construction
91 enclosed in braces may be used instead.
94 represents a full space in the output,
100 Subscripts and superscripts are produced with the keywords
112 .L "e sup {x sup 2 + y sup 2}"
114 $e sup {x sup 2 + y sup 2}$.
122 produces square roots:
123 .L "1 over sqrt {ax sup 2 +bx+c}"
125 $1 over sqrt {ax sup 2 +bx+c}$ .
131 introduce lower and upper
132 limits on arbitrary things:
133 $lim from {n -> inf} sum from 0 to n x sub i$
135 .LR "lim from {n -> inf} sum from 0 to n x sub i" .
137 Left and right brackets, braces, etc., of the right height are made with
141 .L "left [ x sup 2 + y sup 2 over alpha right ] ~=~1"
143 $left [ x sup 2 + y sup 2 over alpha right ] ~=~1$.
147 Legal characters after
151 are braces, brackets, bars,
155 for ceiling and floor,
159 for nothing at all (useful for a right-side-only bracket).
161 Vertical piles of things are made with
167 .L "pile {a above b above c}"
169 $pile {a above b above c}$.
170 There can be an arbitrary number of elements in a pile.
176 center, with different vertical spacing,
181 Matrices are made with
183 .L "matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }"
185 $matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }$.
186 In addition, there is
188 for a right-justified column.
191 Diacritical marks are made with
203 .L "x sub 0 sup prime = f(t) bar + g(t) under"
205 $x sub 0 sup prime = f(t) bar + g(t) under$,
211 Sizes and fonts can be changed with prefix operators
223 Size and fonts can be changed globally in a document by
229 or by the command-line arguments
234 Normally subscripts and superscripts are reduced by
235 3 point sizes from the previous size;
236 this may be changed by the command-line argument
239 Successive display arguments can be lined up.
242 before the desired lineup point in the first equation;
245 at the place that is to line up vertically in subsequent equations.
247 Shorthands may be defined
248 or existing keywords redefined with
255 defines a new token called
257 which will be replaced by
259 whenever it appears thereafter.
262 may be any character that does not occur in
293 Greek letters are spelled out in the desired case, as in
297 Mathematical words like
301 are made Roman automatically.
303 four-character escapes like
305 (\(lh) can be used anywhere.
306 Strings enclosed in double quotes " "
307 are passed through untouched;
308 this permits keywords to be entered as text,
309 and can be used to communicate
314 .TF /sys/lib/troff/font/devutf
316 .B /sys/lib/troff/font/devutf
317 font descriptions for PostScript
324 J. F. Ossanna and B. W. Kernighan,
325 ``Troff User's Manual''.
327 B. W. Kernighan and L. L. Cherry,
328 ``Typesetting Mathematics\(emUser's Guide'',
330 Unix Research System Programmer's Manual,
331 Tenth Edition, Volume 2.
333 To embolden digits, parens, etc.,
334 it is necessary to quote them,
