4.4BSD/usr/share/man/cat1/eqn.0
EQN(1) BSD Reference Manual EQN(1)
NNAAMMEE
eqn - format equations for troff
SSYYNNOOPPSSIISS
eeqqnn [ --rrvvCCNNRR ] [ --dd_c_c ] [ --TT_n_a_m_e ] [ --MM_d_i_r ] [ --ff_F ] [ --ss_n
] [ --pp_n ] [ --mm_n ] [ _f_i_l_e_s... ]
DDEESSCCRRIIPPTTIIOONN
This manual page describes the GNU version of eeqqnn, which
is part of the groff document formatting system. eeqqnn com-
piles descriptions of equations embedded within ttrrooffff
input files into commands that are understood by ttrrooffff.
Normally, it should be invoked using the --ee option of
ggrrooffff. The syntax is quite compatible with Unix eqn. The
output of GNU eqn cannot be processed with Unix troff; it
must be processed with GNU troff. If no files are given
on the command line, the standard input will be read. A
filename of -- will cause the standard input to be read.
eeqqnn searches for the file eeqqnnrrcc using the path
..:://uussrr//sshhaarree//ttmmaacc:://uussrr//sshhaarree//ttmmaacc. If it exists, eqn will
process it before the other input files. The --RR option
prevents this.
GNU eqn does not provide the functionality of neqn: it
does not support low-resolution, typewriter-like devices
(although it may work adequately for very simple input).
OOPPTTIIOONNSS
--CC Recognize ..EEQQ and ..EENN even when followed by a char-
acter other than space or newline.
--NN Don't allow newlines within delimiters. This
option allows eeqqnn to recover better from missing
closing delimiters.
--vv Print the version number.
--rr Only one size reduction.
--mm_n The minimum point-size is _n. eqn will not reduce
the size of subscripts or superscripts to a smaller
size than _n.
--TT_n_a_m_e The output is for device _n_a_m_e. The only effect of
this is to define a macro _n_a_m_e with a value of 11.
Typically eeqqnnrrcc will use this to provide defini-
tions appropriate for the output device. The
default output device is ppss.
--MM_d_i_r Search _d_i_r for eeqqnnrrcc before the default
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EQN(1) BSD Reference Manual EQN(1)
directories.
--RR Don't load eeqqnnrrcc.
--ff_F This is equivalent to a ggffoonntt _F command.
--ss_n This is equivalent to a ggssiizzee _n command. This
option is deprecated. eqn will normally set equa-
tions at whatever the current point size is when
the equation is encountered.
--pp_n This says that subscripts and superscripts should
be _n points smaller than the surrounding text.
This option is deprecated. Normally eqn makes sets
subscripts and superscripts at 70% of the size of
the surrounding text.
UUSSAAGGEE
Only the differences between GNU eqn and Unix eqn are
described here.
Most of the new features of GNU eqn are based on TeX.
There are some references to the differences between TeX
and GNU eqn below; these may safely be ignored if you do
not know TeX.
AAuuttoommaattiicc ssppaacciinngg
eeqqnn gives each component of an equation a type, and
adjusts the spacing between components using that type.
Possible types are:
ordinary an ordinary character such as 1 or _x;
_
operator a large operator such as _>;
binary a binary operator such as +;
relation a relation such as =;
opening a opening bracket such as (;
closing a closing bracket such as );
punctuation a punctutation character such as ,;
inner a subformula contained within brackets;
suppress spacing that suppresses automatic spacing
adjustment.
Components of an equation get a type in one of two ways.
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EQN(1) BSD Reference Manual EQN(1)
ttyyppee _t _e
This yields an equation component that contains _e
but that has type _t, where _t is one of the types
mentioned above. For example, ttiimmeess is defined as
ttyyppee ""bbiinnaarryy"" \\((mmuu
The name of the type doesn't have to be quoted, but
quoting protects from macro expansion.
cchhaarrttyyppee _t _t_e_x_t
Unquoted groups of characters are split up into
individual characters, and the type of each charac-
ter is looked up; this changes the type that is
stored for each character; it says that the charac-
ters in _t_e_x_t from now on have type _t. For example,
cchhaarrttyyppee ""ppuunnccttuuaattiioonn"" ..,,;;::
would make the characters ..,,;;:: have type punctua-
tion whenever they subsequently appeared in an
equation. The type _t can also be lleetttteerr or ddiiggiitt;
in these cases cchhaarrttyyppee changes the font type of
the characters. See the Fonts subsection.
NNeeww pprriimmiittiivveess
_e_1 ssmmaalllloovveerr _e_2
This is similar to oovveerr; ssmmaalllloovveerr reduces the size
of _e_1 and _e_2; it also puts less vertical space
between _e_1 or _e_2 and the fraction bar. The oovveerr
primitive corresponds to the TeX \\oovveerr primitive in
display styles; ssmmaalllloovveerr corresponds to \\oovveerr in
non-display styles.
vvcceenntteerr _e
This vertically centers _e about the math axis. The
math axis is the vertical position about which
characters such as + and - are centered; also it is
the vertical position used for the bar of frac-
tions. For example, ssuumm is defined as
{{ ttyyppee ""ooppeerraattoorr"" vvcceenntteerr ssiizzee ++55 \\((**SS }}
_e_1 aacccceenntt _e_2
This sets _e_2 as an accent over _e_1. _e_2 is assumed
to be at the correct height for a lowercase letter;
_e_2 will be moved down according if _e_1 is taller or
shorter than a lowercase letter. For example, hhaatt
is defined as
aacccceenntt {{ ""^^"" }}
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EQN(1) BSD Reference Manual EQN(1)
ddoottddoott, ddoott, ttiillddee, vveecc and ddyyaadd are also defined
using the aacccceenntt primitive.
_e_1 uuaacccceenntt _e_2
This sets _e_2 as an accent under _e_1. _e_2 is assumed
to be at the correct height for a character without
a descender; _e_2 will be moved down if _e_1 has a
descender. uuttiillddee is pre-defined using uuaacccceenntt as
a tilde accent below the baseline.
sspplliitt ""_t_e_x_t""
This has the same effect as simply
_t_e_x_t
but _t_e_x_t is not subject to macro expansion because
it is quoted; _t_e_x_t will be split up and the spacing
between individual characters will be adjusted.
nnoosspplliitt _t_e_x_t
This has the same effect as
""_t_e_x_t""
but because _t_e_x_t is not quoted it will be subject
to macro expansion; _t_e_x_t will not be split up and
the spacing between individual characters will not
be adjusted.
_e oopppprriimmee
This is a variant of pprriimmee that acts as an operator
on _e. It produces a different result from pprriimmee in
a case such as AA oopppprriimmee ssuubb 11: with oopppprriimmee the 11
will be tucked under the prime as a subscript to
the AA (as is conventional in mathematical typeset-
ting), whereas with pprriimmee the 11 will be a subscript
to the prime character. The precedence of oopppprriimmee
is the same as that of bbaarr and uunnddeerr, which is
higher than that of everything except aacccceenntt and
uuaacccceenntt. In unquoted text a '' that is not the
first character will be treated like oopppprriimmee.
ssppeecciiaall _t_e_x_t _e
This constructs a new object from _e using a
ttrrooffff(1) macro named _t_e_x_t. When the macro is
called, the string 00ss will contain the output for
_e, and the number registers 00ww, 00hh, 00dd, 00sskkeerrnn and
00sskkeeww will contain the width, height, depth, sub-
script kern, and skew of _e. (The _s_u_b_s_c_r_i_p_t _k_e_r_n of
an object says how much a subscript on that object
should be tucked in; the _s_k_e_w of an object says how
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EQN(1) BSD Reference Manual EQN(1)
far to the right of the center of the object an
accent over the object should be placed.) The
macro must modify 00ss so that it will output the
desired result with its origin at the current
point, and increase the current horizontal position
by the width of the object. The number registers
must also be modified so that they correspond to
the result.
For example, suppose you wanted a construct that
`cancels' an expression by drawing a diagonal line
through it.
..EEQQ
ddeeffiinnee ccaanncceell ''ssppeecciiaall CCaa''
..EENN
..ddee CCaa
..ddss 00ss \\ZZ''\\\\**((00ss''\\vv''\\\\nn((00dduu''\\DD''ll \\\\nn((00wwuu --\\\\nn((00hhuu--\\\\nn((00dduu''\\vv''\\\\nn((00hhuu''
....
Then you could cancel an expression _e with
ccaanncceell {{ _e }}
Here's a more complicated construct that draws a
box round an expression:
..EEQQ
ddeeffiinnee bbooxx ''ssppeecciiaall BBxx''
..EENN
..ddee BBxx
..ddss 00ss \\ZZ''\\hh''11nn''\\\\**((00ss''\\
\\ZZ''\\vv''\\\\nn((00dduu++11nn''\\DD''ll \\\\nn((00wwuu++22nn 00''\\DD''ll 00 --\\\\nn((00hhuu--\\\\nn((00dduu--22nn''\\
\\DD''ll --\\\\nn((00wwuu--22nn 00''\\DD''ll 00 \\\\nn((00hhuu++\\\\nn((00dduu++22nn''''\\hh''\\\\nn((00wwuu++22nn''
..nnrr 00ww ++22nn
..nnrr 00dd ++11nn
..nnrr 00hh ++11nn
....
CCuussttoommiizzaattiioonn
The appearance of equations is controlled by a large num-
ber of parameters. These can be set using the sseett command.
sseett _p _n
This sets parameter _p to value _n _; _n is an integer.
For example,
sseett xx__hheeiigghhtt 4455
says that eeqqnn should assume an x height of 0.45
ems.
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EQN(1) BSD Reference Manual EQN(1)
Possible parameters are as follows. Values are in
units of hundredths of an em unless otherwise
stated. These descriptions are intended to be
expository rather than definitive.
mmiinniimmuumm__ssiizzee eeqqnn will not set anything
at a smaller point-size
than this. The value is in
points.
ffaatt__ooffffsseett The ffaatt primitive emboldens
an equation by overprinting
two copies of the equation
horizontally offset by this
amount.
oovveerr__hhaanngg A fraction bar will be
longer by twice this amount
than the maximum of the
widths of the numerator and
denominator; in other
words, it will overhang the
numerator and denominator
by at least this amount.
aacccceenntt__wwiiddtthh When bbaarr or uunnddeerr is
applied to a single charac-
ter, the line will be this
long. Normally, bbaarr or
uunnddeerr produces a line whose
length is the width of the
object to which it applies;
in the case of a single
character, this tends to
produce a line that looks
too long.
ddeelliimmiitteerr__ffaaccttoorr Extensible delimiters pro-
duced with the lleefftt and
rriigghhtt primitives will have
a combined height and depth
of at least this many thou-
sandths of twice the maxi-
mum amount by which the
sub-equation that the
delimiters enclose extends
away from the axis.
ddeelliimmiitteerr__sshhoorrttffaallll Extensible delimiters pro-
duced with the lleefftt and
rriigghhtt primitives will have
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EQN(1) BSD Reference Manual EQN(1)
a combined height and depth
not less than the differ-
ence of twice the maximum
amount by which the sub-
equation that the delim-
iters enclose extends away
from the axis and this
amount.
nnuullll__ddeelliimmiitteerr__ssppaaccee This much horizontal space
is inserted on each side of
a fraction.
ssccrriipptt__ssppaaccee The width of subscripts and
superscripts is increased
by this amount.
tthhiinn__ssppaaccee This amount of space is
automatically inserted
after punctuation charac-
ters.
mmeeddiiuumm__ssppaaccee This amount of space is
automatically inserted on
either side of binary oper-
ators.
tthhiicckk__ssppaaccee This amount of space is
automatically inserted on
either side of relations.
xx__hheeiigghhtt The height of lowercase
letters without ascenders
such as x.
aaxxiiss__hheeiigghhtt The height above the base-
line of the center of char-
acters such as + and -. It
is important that this
value is correct for the
font you are using.
ddeeffaauulltt__rruullee__tthhiicckknneessss This should set to the
thickness of the \\((rruu char-
acter, or the thickness of
horizontal lines produced
with the \\DD escape
sequence.
nnuumm11 The oovveerr command will shift
up the numerator by at
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EQN(1) BSD Reference Manual EQN(1)
least this amount.
nnuumm22 The ssmmaalllloovveerr command will
shift up the numerator by
at least this amount.
ddeennoomm11 The oovveerr command will shift
down the denominator by at
least this amount.
ddeennoomm22 The ssmmaalllloovveerr command will
shift down the denominator
by at least this amount.
ssuupp11 Normally superscripts will
be shifted up by at least
this amount.
ssuupp22 Superscripts within super-
scripts or upper limits or
numerators of ssmmaalllloovveerr
fractions will be shifted
up by at least this amount.
This is usually less than
sup1.
ssuupp33 Superscripts within denomi-
nators or square roots or
subscripts or lower limits
will be shifted up by at
least this amount. This is
usually less than sup2.
ssuubb11 Subscripts will normally be
shifted down by at least
this amount.
ssuubb22 When there is both a sub-
script and a superscript,
the subscript will be
shifted down by at least
this amount.
ssuupp__ddrroopp The baseline of a super-
script will be no more than
this much amount below the
top of the object on which
the superscript is set.
ssuubb__ddrroopp The baseline of a subscript
will be at least this much
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EQN(1) BSD Reference Manual EQN(1)
below the bottom of the
object on which the sub-
script is set.
bbiigg__oopp__ssppaacciinngg11 The baseline of an upper
limit will be at least this
much above the top of the
object on which the limit
is set.
bbiigg__oopp__ssppaacciinngg22 The baseline of a lower
limit will be at least this
much below the bottom of
the object on which the
limit is set.
bbiigg__oopp__ssppaacciinngg33 The bottom of an upper
limit will be at least this
much above the top of the
object on which the limit
is set.
bbiigg__oopp__ssppaacciinngg44 The top of a lower limit
will be at least this much
below the bottom of the
object on which the limit
is set.
bbiigg__oopp__ssppaacciinngg55 This much vertical space
will be added above and
below limits.
bbaasseelliinnee__sseepp The baselines of the rows
in a pile or matrix will
normally be this far apart.
In most cases this should
be equal to the sum of nnuumm11
and ddeennoomm11.
sshhiifftt__ddoowwnn The midpoint between the
top baseline and the bottom
baseline in a matrix or
pile will be shifted down
by this much from the axis.
In most cases this should
be equal to aaxxiiss__hheeiigghhtt.
ccoolluummnn__sseepp This much space will be
added between columns in a
matrix.
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EQN(1) BSD Reference Manual EQN(1)
mmaattrriixx__ssiiddee__sseepp This much space will be
added at each side of a
matrix.
ddrraaww__lliinneess If this is non-zero, lines
will be drawn using the \\DD
escape sequence, rather
than with the \\ll escape
sequence and the \\((rruu char-
acter.
bbooddyy__hheeiigghhtt The amount by which the
height of the equation
exceeds this will be added
as extra space before the
line containing the equa-
tion (using \\xx.) The
default value is 85.
bbooddyy__ddeepptthh The amount by which the
depth of the equation
exceeds this will be added
as extra space after the
line containing the equa-
tion (using \\xx.) The
default value is 35.
nnrrooffff If this is non-zero, then
nnddeeffiinnee will behave like
ddeeffiinnee and ttddeeffiinnee will be
ignored, otherwise ttddeeffiinnee
will behave like ddeeffiinnee and
nnddeeffiinnee will be ignored.
The default value is 0
(This is typically changed
to 1 by the eeqqnnrrcc file for
the aasscciiii and llaattiinn11
devices.)
A more precise description of the role of many of
these parameters can be found in Appendix H of
_T_h_e _T_e_X_b_o_o_k.
MMaaccrrooss
Macros can take arguments. In a macro body, $$_n where _n is
between 1 and 9, will be replaced by the _n_-_t_h argument if
the macro is called with arguments; if there are fewer
than _n arguments, it will be replaced by nothing. A word
containing a left parenthesis where the part of the word
before the left parenthesis has been defined using the
ddeeffiinnee command will be recognized as a macro call with
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EQN(1) BSD Reference Manual EQN(1)
arguments; characters following the left parenthesis up to
a matching right parenthesis will be treated as comma-
separated arguments; commas inside nested parentheses do
not terminate an argument.
ssddeeffiinnee _n_a_m_e _X _a_n_y_t_h_i_n_g _X
This is like the ddeeffiinnee command, but _n_a_m_e will not
be recognized if called with arguments.
iinncclluuddee ""_f_i_l_e""
Include the contents of _f_i_l_e. Lines of _f_i_l_e begin-
ning with ..EEQQ or ..EENN will be ignored.
iiffddeeff _n_a_m_e _X _a_n_y_t_h_i_n_g _X
If _n_a_m_e has been defined by ddeeffiinnee (or has been
automatically defined because _n_a_m_e is the output
device) process _a_n_y_t_h_i_n_g; otherwise ignore _a_n_y_-
_t_h_i_n_g. _X can be any character not appearing in
_a_n_y_t_h_i_n_g.
FFoonnttss
eeqqnn normally uses at least two fonts to set an equation:
an italic font for letters, and a roman font for every-
thing else. The existing ggffoonntt command changes the font
that is used as the italic font. By default this is II.
The font that is used as the roman font can be changed
using the new ggrrffoonntt command.
ggrrffoonntt _f
Set the roman font to _f.
The iittaalliicc primitive uses the current italic font set by
ggffoonntt; the rroommaann primitive uses the current roman font set
by ggrrffoonntt. There is also a new ggbbffoonntt command, which
changes the font used by the bboolldd primitive. If you only
use the rroommaann, iittaalliicc and bboolldd primitives to changes fonts
within an equation, you can change all the fonts used by
your equations just by using ggffoonntt, ggrrffoonntt and ggbbffoonntt com-
mands.
You can control which characters are treated as letters
(and therefore set in italics) by using the cchhaarrttyyppee com-
mand described above. A type of lleetttteerr will cause a char-
acter to be set in italic type. A type of ddiiggiitt will
cause a character to be set in roman type.
FFIILLEESS
//uussrr//sshhaarree//ttmmaacc//eeqqnnrrcc Initialization file.
BBUUGGSS
Inline equations will be set at the point size that is
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EQN(1) BSD Reference Manual EQN(1)
current at the beginning of the input line.
SSEEEE AALLSSOO
ggrrooffff(1), ttrrooffff(1), ggrrooffff__ffoonntt(5), _T_h_e _T_e_X_b_o_o_k
Groff Version 1.08 6 October 1992 12