


EQN(1)		    UNIX Programmer's Manual		   EQN(1)



NAME
     eqn, neqn, checkeq - typeset mathematics

SYNOPSIS
     eqn [ -dxy ] [ -pn ] [ -sn ] [ -fn ] [ file ] ...
     checkeq [ file ] ...

DESCRIPTION
     _E_q_n is a troff(1) preprocessor for typesetting mathematics
     on a Graphic Systems phototypesetter, _n_e_q_n 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 _e_q_n input.  Delimiters may be set to characters _x
     and _y with the command-line argument -d_x_y or (more commonly)
     with `delim _x_y' 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 _c_h_e_c_k_e_q reports missing or unbalanced delimiters
     and .EQ/.EN pairs.

     Tokens within _e_q_n 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 _s_u_b _i makes _x_i, _a _s_u_b _i _s_u_p _2 produces
     _a_i
      2
       , and _e _s_u_p {_x _s_u_p _2 + _y _s_u_p _2} gives _e
						    _x2+_y2
						      .


     Fractions are made with over: _a _o_v_e_r _b yields
						     _b

						       _a_.


     sqrt makes square roots: _1 _o_v_e_r _s_q_r_t {_a_x _s_u_p _2 +_b_x+_c}

     results in
                v/~~~~~~~~_a_x
		      2
			+_b_x+_c

		     1_________ .





Printed 11/26/99	   May 9, 1986				1






EQN(1)		    UNIX Programmer's Manual		   EQN(1)



     The keywords from and to introduce lower and upper limits on

     arbitrary things:
			     _n->oo
			    lim
			       0
				 _>_~
				 _n
				  _x_i is made with _l_i_m _f_r_o_m {_n-> _i_n_f }

     _s_u_m _f_r_o_m _0 _t_o _n _x _s_u_b _i.

     Left and right brackets, braces, etc., of the right height
     are made with left and right: _l_e_f_t [ _x _s_u_p _2 + _y _s_u_p _2 _o_v_e_r

     _a_l_p_h_a _r_i_g_h_t ] ~=~_1 produces
				 |
				  |
				  |
				    _x
				      2
					+
					   _o(

                                      _y
                                       2
				      __
					|
					|
					|
					   = 1.	The right clause

     is optional.  Legal characters after 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,

     and rpile: _p_i_l_e {_a _a_b_o_v_e _b _a_b_o_v_e _c} produces
						   _c
						     _b
						     _a

						      .  There can

     be an arbitrary number of elements in a pile.  lpile left-
     justifies, pile and cpile center, with different vertical
     spacing, and rpile right justifies.

     Matrices are made with matrix: _m_a_t_r_i_x { _l_c_o_l { _x _s_u_b _i _a_b_o_v_e

     _y _s_u_b _2 } _c_c_o_l { _1 _a_b_o_v_e _2 } } produces
						 _y2

                                             _x_i


                                                 2

						   1

						    .  In addition,

     there is rcol for a right-justified column.

     Diacritical marks are made with dot, dotdot, hat, tilde,
     bar, vec, dyad, and under: _x _d_o_t = _f(_t) _b_a_r is _x.=_f(_t)~~~~, _y
     _d_o_t_d_o_t _b_a_r ~=~ _n _u_n_d_e_r is _y..~ = _n_, and _x _v_e_c ~=~ _y _d_y_a_d 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 -s_n and -f_n.

     Normally subscripts and superscripts are reduced by 3 point
     sizes from the previous size; this may be changed by the
     command-line argument -p_n.

     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: _d_e_f_i_n_e _t_h_i_n_g % _r_e_p_l_a_c_e_m_e_n_t % defines a new
     token called _t_h_i_n_g which will be replaced by _r_e_p_l_a_c_e_m_e_n_t



Printed 11/26/99	   May 9, 1986				2






EQN(1)		    UNIX Programmer's Manual		   EQN(1)



     whenever it appears thereafter.  The % may be any character
     that does not occur in _r_e_p_l_a_c_e_m_e_n_t.

     Keywords like _s_u_m (_>_~) _i_n_t () _i_n_f (oo) and shorthands like >=
     (>_) -> (->), and != (=/) are recognized.  Greek letters are
     spelled out in the desired case, as in _a_l_p_h_a or _G_A_M_M_A.
     Mathematical words like sin, cos, log are made Roman
     automatically.  _T_r_o_f_f(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
     _t_r_o_f_f when all else fails.

SEE ALSO
     troff(1), tbl(1), ms(7), eqnchar(7)
     B. W. Kernighan and L. L. Cherry, _T_y_p_e_s_e_t_t_i_n_g _M_a_t_h_e_m_a_t_i_c_s-
     _U_s_e_r'_s _G_u_i_d_e
     J. F. Ossanna, _N_R_O_F_F/_T_R_O_F_F _U_s_e_r'_s _M_a_n_u_a_l

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

































Printed 11/26/99	   May 9, 1986				3



