merge from VERSION_1_12:

[mandoc.git] / eqn.7

diff --git a/eqn.7 b/eqn.7
index ca0fb622d58a74e157c156766016c0aa46099cf4..dcbad41cc15bd865c1b9d356ba327a839dde1b4b 100644 (file)
--- a/eqn.7
+++ b/eqn.7
@@ -1,4 +1,4 @@
-.\"    $Id: eqn.7,v 1.6 2011/07/21 11:34:53 kristaps Exp $
+.\"    $Id: eqn.7,v 1.29 2013/07/13 19:41:16 schwarze Exp $

 .\"
 .\" Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"
 .\"
 .\" Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\"


@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"

-.Dd $Mdocdate: July 21 2011 $
+.Dd $Mdocdate: July 13 2013 $

 .Dt EQN 7
 .Os
 .Sh NAME
 .Dt EQN 7
 .Os
 .Sh NAME


@@ -23,18 +23,23 @@
 .Sh DESCRIPTION
 The
 .Nm eqn
 .Sh DESCRIPTION
 The
 .Nm eqn

-language is a equation-formatting language.
+language is an equation-formatting language.

 It is used within
 .Xr mdoc 7
 and
 .Xr man 7
 .Ux
 manual pages.
 It is used within
 .Xr mdoc 7
 and
 .Xr man 7
 .Ux
 manual pages.

-This manual describes the subset of the
+It describes the
+.Em structure
+of an equation, not its mathematical meaning.
+This manual describes the

 .Nm
 language accepted by the
 .Xr mandoc 1
 .Nm
 language accepted by the
 .Xr mandoc 1

-utility.
+utility, which corresponds to the Second Edition eqn specification (see
+.Sx SEE ALSO
+for references).

 .Pp
 Equations within
 .Xr mdoc 7
 .Pp
 Equations within
 .Xr mdoc 7


@@ -59,26 +64,60 @@ these are not the same as
 macros, and may only be invoked as
 .Sq \&.EQ .
 .Pp
 macros, and may only be invoked as
 .Sq \&.EQ .
 .Pp

-The equation grammar is as follows:
+The equation grammar is as follows, where quoted strings are
+case-sensitive literals in the input:

 .Bd -literal -offset indent
 eqn     : box | eqn box
 box     : text
 .Bd -literal -offset indent
 eqn     : box | eqn box
 box     : text

-        | DEFINE text text
-        | SET text text
-        | UNDEF text
-text    : TEXT
+        | \*q{\*q eqn \*q}\*q
+        | \*qdefine\*q text text
+        | \*qndefine\*q text text
+        | \*qtdefine\*q text text
+        | \*qgfont\*q text
+        | \*qgsize\*q text
+        | \*qset\*q text text
+        | \*qundef\*q text
+        | box pos box
+        | box mark
+        | \*qmatrix\*q \*q{\*q [col \*q{\*q list \*q}\*q ]*
+        | pile \*q{\*q list \*q}\*q
+        | font box
+        | \*qsize\*q text box
+        | \*qleft\*q text eqn [\*qright\*q text]
+col     : \*qlcol\*q | \*qrcol\*q | \*qccol\*q | \*qcol\*q
+text    : [^space\e\*q]+ | \e\*q.*\e\*q
+pile    : \*qlpile\*q | \*qcpile\*q | \*qrpile\*q | \*qpile\*q
+pos     : \*qover\*q | \*qsup\*q | \*qsub\*q | \*qto\*q | \*qfrom\*q
+mark   : \*qdot\*q | \*qdotdot\*q | \*qhat\*q | \*qtilde\*q | \*qvec\*q
+        | \*qdyad\*q | \*qbar\*q | \*qunder\*q
+font    : \*qroman\*q | \*qitalic\*q | \*qbold\*q | \*qfat\*q
+list    : eqn
+        | list \*qabove\*q eqn
+space   : [\e^~ \et]

 .Ed
 .Pp
 .Ed
 .Pp

-Data in TEXT form is a non-empty sequence of non-space characters or a
-non-empty quoted string.
-Unless within a quoted string, white-space (and enclosing literal quote
-pairs) is thrown away.
-Quoted strings are not scanned for replacement definitions.
+White-space consists of the space, tab, circumflex, and tilde
+characters.
+If within a quoted string, these space characters are retained.
+Quoted strings are also not scanned for replacement definitions.
+.Pp
+The following text terms are translated into a rendered glyph, if
+available: alpha, beta, chi, delta, epsilon, eta, gamma, iota, kappa,
+lambda, mu, nu, omega, omicron, phi, pi, psi, rho, sigma, tau, theta,
+upsilon, xi, zeta, DELTA, GAMMA, LAMBDA, OMEGA, PHI, PI, PSI, SIGMA,
+THETA, UPSILON, XI, inter (intersection), union (union), prod (product),
+int (integral), sum (summation), grad (gradient), del (vector
+differential), times (multiply), cdot (centre-dot), nothing (zero-width
+space), approx (approximately equals), prime (prime), half (one-half),
+partial (partial differential), inf (infinity), >> (much greater), <<
+(much less), \-> (left arrow), <\- (right arrow), += (plus-minus), !=
+(not equal), == (equivalence), <= (less-than-equal), and >=
+(more-than-equal).

 .Pp
 The following control statements are available:
 .Bl -tag -width Ds
 .It Cm define
 .Pp
 The following control statements are available:
 .Bl -tag -width Ds
 .It Cm define

-Replace all occurances of a key with a value.
+Replace all occurrences of a key with a value.

 Its syntax is as follows:
 .Pp
 .D1 define Ar key cvalc
 Its syntax is as follows:
 .Pp
 .D1 define Ar key cvalc


@@ -93,13 +132,15 @@ This allows for arbitrary enclosure of terms (not just quotes), such as
 .D1 define Ar foo cbar bazc
 .Pp
 It is an error to have an empty
 .D1 define Ar foo cbar bazc
 .Pp
 It is an error to have an empty

-.Ar key or
+.Ar key
+or

 .Ar val .
 Note that a quoted
 .Ar key
 causes errors in some
 .Nm
 implementations and should not be considered portable.
 .Ar val .
 Note that a quoted
 .Ar key
 causes errors in some
 .Nm
 implementations and should not be considered portable.

+It is not expanded for replacements.

 Definitions may refer to other definitions; these are evaluated
 recursively when text replacement occurs and not when the definition is
 created.
 Definitions may refer to other definitions; these are evaluated
 recursively when text replacement occurs and not when the definition is
 created.


@@ -112,9 +153,42 @@ foo bar 'baz'
 .Ed
 .Pp
 Self-referencing definitions will raise an error.
 .Ed
 .Pp
 Self-referencing definitions will raise an error.

+The
+.Cm ndefine
+statement is a synonym for
+.Cm define ,
+while
+.Cm tdefine
+is discarded.
+.It Cm gfont
+Set the default font of subsequent output.
+Its syntax is as follows:
+.Pp
+.D1 gfont Ar font
+.Pp
+In mandoc, this value is discarded.
+.It Cm gsize
+Set the default size of subsequent output.
+Its syntax is as follows:
+.Pp
+.D1 gsize Ar size
+.Pp
+The
+.Ar size
+value should be an integer.

 .It Cm set
 Set an equation mode.
 .It Cm set
 Set an equation mode.

-Both arguments are thrown away.
+In mandoc, both arguments are thrown away.
+Its syntax is as follows:
+.Pp
+.D1 set Ar key val
+.Pp
+The
+.Ar key
+and
+.Ar val
+are not expanded for replacements.
+This statement is a GNU extension.

 .It Cm undef
 Unset a previously-defined key.
 Its syntax is as follows:
 .It Cm undef
 Unset a previously-defined key.
 Its syntax is as follows:


@@ -124,6 +198,10 @@ Its syntax is as follows:
 Once invoked, the definition for
 .Ar key
 is discarded.
 Once invoked, the definition for
 .Ar key
 is discarded.

+The
+.Ar key
+is not expanded for replacements.
+This statement is a GNU extension.

 .El
 .Sh COMPATIBILITY
 This section documents the compatibility of mandoc
 .El
 .Sh COMPATIBILITY
 This section documents the compatibility of mandoc


@@ -138,6 +216,26 @@ The text string
 .Sq \e\*q
 is interpreted as a literal quote in troff.
 In mandoc, this is interpreted as a comment.
 .Sq \e\*q
 is interpreted as a literal quote in troff.
 In mandoc, this is interpreted as a comment.

+.It
+In troff, The circumflex and tilde white-space symbols map to
+fixed-width spaces.
+In mandoc, these characters are synonyms for the space character.
+.It
+The troff implementation of
+.Nm
+allows for equation alignment with the
+.Cm mark
+and
+.Cm lineup
+tokens.
+mandoc discards these tokens.
+The
+.Cm back Ar n ,
+.Cm fwd Ar n ,
+.Cm up Ar n ,
+and
+.Cm down Ar n
+commands are also ignored.

 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,
 .El
 .Sh SEE ALSO
 .Xr mandoc 1 ,


@@ -167,7 +265,7 @@ In mandoc, this is interpreted as a comment.
 .%D 1978
 .Re
 .Sh HISTORY
 .%D 1978
 .Re
 .Sh HISTORY

-The eqn utility, a preprocessor for troff, was originally written by 
+The eqn utility, a preprocessor for troff, was originally written by

 Brian W. Kernighan and Lorinda L. Cherry in 1975.
 The GNU reimplementation of eqn, part of the GNU troff package, was
 released in 1989 by James Clark.
 Brian W. Kernighan and Lorinda L. Cherry in 1975.
 The GNU reimplementation of eqn, part of the GNU troff package, was
 released in 1989 by James Clark.


@@ -178,4 +276,4 @@ was added in 2011.
 This
 .Nm
 reference was written by
 This
 .Nm
 reference was written by

-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
+.An Kristaps Dzonsons Aq Mt kristaps@bsd.lv .