eqn.1 (5655B)
1 .TH EQN 1 2 .EQ 3 delim $$ 4 .EN 5 .SH NAME 6 eqn \- typeset mathematics 7 .SH SYNOPSIS 8 .B eqn 9 [ 10 .I option ... 11 ] 12 [ 13 .I file ... 14 ] 15 .SH DESCRIPTION 16 .I Eqn 17 is a 18 .MR troff (1) 19 preprocessor 20 for typesetting mathematics 21 on a typesetter. 22 Usage is almost always 23 .IP 24 .L 25 eqn file ... | troff 26 .PP 27 If no files are specified, 28 .I eqn 29 reads from the standard input. 30 .I Eqn 31 prepares output for the typesetter 32 named in the 33 .BI -T dest 34 option (default 35 .BR -Tutf ; 36 see 37 .MR troff (1) ). 38 When run with other preprocessor filters, 39 .I eqn 40 usually comes last. 41 .PP 42 A line beginning with 43 .B .EQ 44 marks the start of an equation; 45 the end of an equation 46 is marked by a line beginning with 47 .BR .EN . 48 Neither of these lines is altered, 49 so they may be defined in macro packages 50 to get 51 centering, numbering, etc. 52 It is also possible to set two characters 53 as `delimiters'; 54 text between delimiters is also 55 .I eqn 56 input. 57 Delimiters may be set to characters 58 .I x 59 and 60 .I y 61 with the option 62 .BI -d xy 63 or (more commonly) with 64 .B delim 65 .I xy 66 between 67 .B .EQ 68 and 69 .BR .EN . 70 Left and right delimiters may be identical. 71 (They are customarily taken to be 72 $font L "$$" )$. 73 Delimiters are turned off by 74 .LR "delim off" . 75 All text that is neither between delimiters nor between 76 .B .EQ 77 and 78 .B .EN 79 is passed through untouched. 80 .PP 81 Tokens within 82 .I eqn 83 are separated by 84 spaces, tabs, newlines, braces, double quotes, 85 tildes or circumflexes. 86 Braces {} are used for grouping; 87 generally speaking, 88 anywhere a single character like 89 .L x 90 could appear, a complicated construction 91 enclosed in braces may be used instead. 92 Tilde 93 .L ~ 94 represents a full space in the output, 95 circumflex 96 .L ^ 97 half as much. 98 .PP 99 .vs 13p 100 Subscripts and superscripts are produced with the keywords 101 .B sub 102 and 103 .BR sup . 104 Thus 105 .L "x sub i" 106 makes 107 $x sub i$, 108 .L "a sub i sup 2" 109 produces 110 $a sub i sup 2$, 111 and 112 .L "e sup {x sup 2 + y sup 2}" 113 gives 114 $e sup {x sup 2 + y sup 2}$. 115 .PP 116 .B Over 117 makes fractions: 118 .L "a over b" 119 yields $a over b$. 120 .PP 121 .B Sqrt 122 produces square roots: 123 .L "1 over sqrt {ax sup 2 +bx+c}" 124 results in 125 $1 over sqrt {ax sup 2 +bx+c}$ . 126 .PP 127 The keywords 128 .B from 129 and 130 .B to 131 introduce lower and upper 132 limits on arbitrary things: 133 $lim from {n -> inf} sum from 0 to n x sub i$ 134 is made with 135 .LR "lim from {n -> inf} sum from 0 to n x sub i" . 136 .PP 137 Left and right brackets, braces, etc., of the right height are made with 138 .B left 139 and 140 .BR right : 141 .L "left [ x sup 2 + y sup 2 over alpha right ] ~=~1" 142 produces 143 $left [ x sup 2 + y sup 2 over alpha right ] ~=~1$. 144 The 145 .B right 146 clause is optional. 147 Legal characters after 148 .B left 149 and 150 .B right 151 are braces, brackets, bars, 152 .B c 153 and 154 .B f 155 for ceiling and floor, 156 and 157 .B 158 "" 159 for nothing at all (useful for a right-side-only bracket). 160 .PP 161 Vertical piles of things are made with 162 .BR pile , 163 .BR lpile , 164 .BR cpile , 165 and 166 .BR rpile : 167 .L "pile {a above b above c}" 168 produces 169 $pile {a above b above c}$. 170 There can be an arbitrary number of elements in a pile. 171 .B lpile 172 left-justifies, 173 .B pile 174 and 175 .B cpile 176 center, with different vertical spacing, 177 and 178 .B rpile 179 right justifies. 180 .PP 181 Matrices are made with 182 .BR matrix : 183 .L "matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }" 184 produces 185 $matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }$. 186 In addition, there is 187 .B rcol 188 for a right-justified column. 189 .PP 190 .vs 12p 191 Diacritical marks are made with 192 .BR prime , 193 .BR dot , 194 .BR dotdot , 195 .BR hat , 196 .BR tilde , 197 .BR bar , 198 .BR under , 199 .BR vec , 200 .BR dyad , 201 and 202 .BR under : 203 .L "x sub 0 sup prime = f(t) bar + g(t) under" 204 is 205 $x sub 0 sup prime = f(t) bar + g(t) under$, 206 and 207 .L "x vec = y dyad" 208 is 209 $x vec = y dyad$. 210 .PP 211 Sizes and fonts can be changed with prefix operators 212 .B size 213 .IR n , 214 .B size 215 .BI ± n \f1, 216 .BR fat , 217 .BR roman , 218 .BR italic , 219 .BR bold , 220 or 221 .BR font 222 .IR n . 223 Size and fonts can be changed globally in a document by 224 .B gsize 225 .I n 226 and 227 .B gfont 228 .IR n , 229 or by the command-line arguments 230 .BI -s n 231 and 232 .BI -f n\f1. 233 .PP 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 237 .BI -p n\f1. 238 .PP 239 Successive display arguments can be lined up. 240 Place 241 .B mark 242 before the desired lineup point in the first equation; 243 place 244 .B lineup 245 at the place that is to line up vertically in subsequent equations. 246 .PP 247 Shorthands may be defined 248 or existing keywords redefined with 249 .BR define : 250 .L define 251 .I thing 252 .L % 253 .I replacement 254 .L % 255 defines a new token called 256 .I thing 257 which will be replaced by 258 .I replacement 259 whenever it appears thereafter. 260 The 261 .L % 262 may be any character that does not occur in 263 .LR replacement . 264 .PP 265 Keywords like 266 .L sum 267 .EQ 268 ( sum ), 269 .EN 270 .L int 271 .EQ 272 ( int ), 273 .EN 274 .L inf 275 .EQ 276 ( inf ), 277 .EN 278 and shorthands like 279 .L >= 280 .EQ 281 (>=), 282 .EN 283 .L -> 284 .EQ 285 (->), 286 .EN 287 and 288 .L != 289 .EQ 290 ( != ) 291 .EN 292 are recognized. 293 Greek letters are spelled out in the desired case, as in 294 .L alpha 295 or 296 .LR GAMMA . 297 Mathematical words like 298 .LR sin , 299 .LR cos , 300 .L log 301 are made Roman automatically. 302 .MR Troff (1) 303 four-character escapes like 304 .L \e(lh 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 310 with 311 .I troff 312 when all else fails. 313 .SH FILES 314 .TF /sys/lib/troff/font/devutf 315 .TP 316 .B /sys/lib/troff/font/devutf 317 font descriptions for PostScript 318 .SH SOURCE 319 .B \*9/src/cmd/eqn 320 .SH "SEE ALSO" 321 .IR troff (1), 322 .MR tbl (1) 323 .br 324 J. F. Ossanna and B. W. Kernighan, 325 ``Troff User's Manual''. 326 .br 327 B. W. Kernighan and L. L. Cherry, 328 ``Typesetting Mathematics\(emUser's Guide'', 329 .I 330 Unix Research System Programmer's Manual, 331 Tenth Edition, Volume 2. 332 .SH BUGS 333 To embolden digits, parens, etc., 334 it is necessary to quote them, 335 as in 336 .LR bold\ "12.3" . 337 .EQ 338 delim off 339 .EN