1.\" Copyright (c) 1990 Regents of the University of California. 2.\" All rights reserved. The Berkeley software License Agreement 3.\" specifies the terms and conditions for redistribution. 4.\" 5.\" @(#)eqn.1 6.5 (Berkeley) 03/13/91 6.\" 7.Vx 8.Dd 9.Dt EQN 1 10.Os ATT 7th 11.EQ 12delim $$ 13.EN 14.Sh NAME 15.Nm eqn, neqn , checkeq 16.Nd typeset mathematics 17.Sh SYNOPSIS 18.Nm eqn 19.Oo 20.Op Fl d Ar xy 21.Op Fl p Ar n 22.Op Fl s Ar n 23.Op Fl f Ar n 24.Op file 25\&... 26.Nm checkeq 27.Op file 28\&... 29.Sh DESCRIPTION 30.Nm Eqn 31is a 32.Xr troff 1 33preprocessor 34for typesetting mathematics 35on a Graphic Systems phototypesetter, 36.Xr neqn 37on terminals. 38Usage is almost always 39.Pp 40.Dl eqn file ... | troff 41.Pp 42.Dl neqn file ... | nroff 43.Pp 44If no files are specified, 45these programs 46read from the standard input. 47A line beginning with `.EQ' marks the start of an equation; 48the end of an equation 49is marked by a line beginning with `.EN'. 50Neither of these lines is altered, 51so they may be defined in macro packages 52to get 53centering, numbering, etc. 54It is also possible to set two characters as `delimiters'; 55subsequent text between delimiters is also treated as 56.Nm eqn 57input. 58Delimiters may be set to characters 59.Ar x 60and 61.Ar y 62with the command-line argument 63.Fl d xy 64or (more commonly) with 65`delim 66.Ar xy ' 67between .EQ and .EN. 68The left and right delimiters may be identical. 69Delimiters are turned off by `delim off'. 70All text that is neither between delimiters nor between .EQ and .EN 71is passed through untouched. 72.Pp 73The program 74.Nm checkeq 75reports missing or unbalanced delimiters and .EQ/.EN pairs. 76.Pp 77Tokens within 78.Nm eqn 79are separated by 80spaces, tabs, newlines, braces, double quotes, 81tildes or circumflexes. 82Braces {} are used for grouping; 83generally speaking, 84anywhere a single character like 85.Ar x 86could appear, a complicated construction 87enclosed in braces may be used instead. 88Tilde ~ represents a full space in the output, 89circumflex ^ half as much. 90.Pp 91.vs 13p 92Subscripts and superscripts are produced with the keywords 93.Ic sub 94and 95.Ic sup . 96Thus 97.Ar "x sub i" 98makes 99$x sub i$, 100.Ar "a sub i sup 2" 101produces 102$a sub i sup 2$, 103and 104.Ar "e sup {x sup 2 + 105.Ar y sup 2}" 106gives 107$e sup {x sup 2 + y sup 2}$. 108.Pp 109Fractions are made with 110.Ic over : 111.Ar "a over b" 112yields $a over b$. 113.Pp 114.Ic sqrt 115makes square roots: 116.Ar "1 over sqrt 117.Ar {ax sup 2 +bx+c}" 118results in 119$1 over sqrt {ax sup 2 +bx+c}$ . 120.Pp 121The keywords 122.Ic from 123and 124.Ic to 125introduce lower and upper limits on arbitrary things: 126$lim from {n-> inf} sum from 0 to n x sub i$ 127is made with 128.Ar "lim from {n\-> inf } 129.Ar sum from 0 to n x 130.Ar sub i." 131.Pp 132Left and right brackets, braces, etc., of the right height are made with 133.Ic left 134and 135.Ic right : 136.Op Ar "left 137.Ar x sup 2 + y sup 2 138.AR over alpha right 139.Ar \&~=~1" 140produces 141$left [ x sup 2 + y sup 2 over alpha right ] ~=~1$. 142The 143.Ic right 144clause is optional. 145Legal characters after 146.Ic left 147and 148.Ic right 149are braces, brackets, bars, 150.Ic c 151and 152.Ic f 153for ceiling and floor, 154and "" for nothing at all (useful for a right-side-only bracket). 155.Pp 156Vertical piles of things are made with 157.Ic pile , 158.Ic lpile , 159.Ic cpile , 160and 161.Ic rpile : 162.Ar "pile {a above b above c}" 163produces 164$pile {a above b above c}$. 165There can be an arbitrary number of elements in a pile. 166.Ic lpile 167left-justifies, 168.Ic pile 169and 170.Ic cpile 171center, with different vertical spacing, 172and 173.Ic rpile 174right justifies. 175.Pp 176Matrices are made with 177.Ic matrix : 178.Ar "matrix { lcol { x sub i 179.Ar above y sub 2 } ccol { 180.Ar 1 above 2 } }" 181produces 182$matrix { lcol { x sub i above y sub 2 } ccol { 1 above 2 } }$. 183In addition, there is 184.Ic rcol 185for a right-justified column. 186.Pp 187.vs 12p 188Diacritical marks are made with 189.Ic dot , 190.Ic dotdot , 191.Ic hat , 192.Ic tilde , 193.Ic bar , 194.Ic vec , 195.Ic dyad , 196and 197.Ic under : 198.Ar "x dot \&= f(t) bar" 199is 200$x dot = f(t) bar$, 201.Ar "y dotdot bar \&~=~ 202.Ar n under" 203is 204$y dotdot bar ~=~ n under$, 205and 206.Ar "x vec \&~=~ y dyad" 207is 208$x vec ~=~ y dyad$. 209.Pp 210Sizes and font can be changed with 211.Ic size 212.Op Ar n 213or 214.Ic size 215.Sf Sy \(+- n, 216.Ic roman , 217.Ic italic , 218.Ic bold , 219and 220.Ic font 221.Ar n. 222Size and fonts can be changed globally in a document by 223.Ic gsize 224.Ar n 225and 226.Ic gfont 227.Ar n , 228or by the command-line arguments 229.Cx Fl s 230.Ar n 231.Cx 232and 233.Cx Fl f 234.Ar n 235.Cx . 236.Cx 237.Pp 238Normally subscripts and superscripts are reduced by 2393 point sizes from the previous size; 240this may be changed by the command-line argument 241.Cx Fl p 242.Ar n . 243.Cx 244.Pp 245Successive display arguments can be lined up. 246Place 247.Ic mark 248before the desired lineup point in the first equation; 249place 250.Ic lineup 251at the place that is to line up vertically in subsequent equations. 252.Pp 253Shorthands may be defined 254or existing keywords redefined with 255.Ic define : 256.Ar "define thing \&% replacement \&%" 257defines a new token called 258.Ar thing 259which will be replaced by 260.Ar replacement 261whenever it appears thereafter. 262The 263.Ic \&% 264may be any character that does not occur in 265.Ar replacement . 266.Pp 267Keywords like 268.Ar sum 269.EQ 270( sum ) 271.EN 272.Ar int 273.EQ 274( int ) 275.EN 276.Ar inf 277.EQ 278( inf ) 279.EN 280and shorthands like 281>= 282.EQ 283(>=) 284.EN 285\-> 286.EQ 287(->), 288.EN 289and 290!= 291.EQ 292( != ) 293.EN 294are recognized. 295Greek letters are spelled out in the desired case, as in 296.Ar alpha 297or 298.Ar GAMMA . 299Mathematical words like sin, cos, log are made Roman automatically. 300.Xr Troff 1 301four-character escapes like \e(bs (\(bs) 302can be used anywhere. 303Strings enclosed in double quotes "..." 304are passed through untouched; 305this permits keywords to be entered as text, 306and can be used to communicate 307with 308.Xr troff 1 309when all else fails. 310.Sh SEE ALSO 311.Xr troff 1 , 312.Xr tbl 1 , 313.Xr ms 7 , 314.Xr eqnchar 7 315.br 316B. W. Kernighan and L. L. Cherry, 317.Em Typesetting Mathematics\-User's Guide 318.Br 319J. F. Ossanna, 320.Em NROFF/TROFF User's Manual 321.Sh HISTORY 322.Nm Eqn 323appeared in Version 6 AT&T Unix. 324.Sh BUGS 325.Pp 326To embolden digits, parens, etc., 327it is necessary to quote them, 328as in `bold "12.3"'. 329