-.\" $Id: eqn.7,v 1.24 2011/07/23 18:44:42 kristaps Exp $
+.\" $Id: eqn.7,v 1.28 2011/09/25 18:37:09 schwarze Exp $
.\"
.\" Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
.\"
.\" 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 23 2011 $
+.Dd $Mdocdate: September 25 2011 $
.Dt EQN 7
.Os
.Sh NAME
.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 describes the
+.Em structure
+of an equation, not its mathematical meaning.
This manual describes the
.Nm
language accepted by the
.Xr mandoc 1
-utility, which correspond to the Second Edition eqn specification (see
+utility, which corresponds to the Second Edition eqn specification (see
.Sx SEE ALSO
for references).
.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
.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
This
.Nm
reference was written by
-.An Kristaps Dzonsons Aq kristaps@bsd.lv .
+.An Kristaps Dzonsons ,
+.Mt kristaps@bsd.lv .