EQN(1-BSD)          RISC/os Reference Manual           EQN(1-BSD)



NAME
     eqn, neqn, checkeq - typeset mathematics

SYNOPSIS
     eqn [ -dxy ] [ -pn ] [ -sn ] [ -fn ] [ files ] ...
     neqn [ -dxy ] [ -pn ] [ -sn ] [ -fn ] [ files ] ...  checkeq
     [ files ] ...

DESCRIPTION
     eqn is a troff(1) preprocessor for typesetting mathematics
     on a Graphic Systems phototypesetter, neqn on terminals.
     Usage is almost always

          eqn file ... | troff
          neqn file ... | nroff

     If no files are specified, these programs 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, etc.  It is also possible to set two characters
     as `delimiters'; subsequent text between delimiters is also
     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 identical.  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, newlines,
     braces, double quotes, tildes or circumflexes.  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. Thus x sub i makes x , a sub i sup 2 produces
      2                               i       x2+y2
     ai, and e sup {x sup 2 + y sup 2} gives e     .
                                                    a
     Fractions are made with over:  a over b yields b.

     sqrt makes squar1
e_roots:  1 over sqrt {ax sup 2 +bx+c}
     results in   ________ .
                \|ax2+bx+c





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EQN(1-BSD)          RISC/os Reference Manual           EQN(1-BSD)



     The keywords from and to introduce lower and upper limits on
                             n
     arbitrary things:   lim Σxi is made with lim from {n-> inf }
     sum from 0 to n x sn
u-
b>i
o.
o0

     Left and right brackets, braces, etc., of the right height
     are made with left and right: left [ x sup 2 + y sup 2 over
                                 | 2 y2|
     alpha right ] ~=~1 produces |x +Α | = 1.  The right clause
     is optional.  Legal character
|s afte
|r 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,
                                                   a
     and rpile:  pile {a above b above c} produces b.  There can
     be an arbitrary number of elements in a pile. clpile left-
     justifies, pile and cpile center, with different vertical
     spacing, and rpile right justifies.

     Matrices are made with matrix:  matrix { lcol { x sub i
                                                   xi  1
     above y sub 2 } ccol { 1 above 2 } } produces      .  In
                                                   y2  2
     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 is x=f(t), y
     dotdot bar ~=~ n under is y  = n, and x vec ~=~ y dyad is
     x = y.

     Sizes and font can be changed with size n or size +n, roman,
     italic, bold, and font n. Size and fonts can be changed glo-
     bally 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 point
     sizes 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 subse-
     quent 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.




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EQN(1-BSD)          RISC/os Reference Manual           EQN(1-BSD)



     Keywords like sum (Σ) int (∫) inf (oo) 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, log are made Roman
     automatically.  troff(1) four-character escapes like \(bs ()
     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.

SEE ALSO
     troff(1), tbl(1).
     B. W. Kernighan and L. L. Cherry, Typesetting Mathematics-
     User's Guide
     Documenter's Work Bench.

BUGS
     To embolden digits, parens, etc., it is necessary to quote
     them, as in `bold "12.3"'.




































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