diff options
| -rw-r--r-- | eqn.7 | 51 |
1 files changed, 29 insertions, 22 deletions
@@ -44,28 +44,16 @@ specification (see .Sx SEE ALSO for references). .Pp -Equations within -.Xr mdoc 7 -or -.Xr man 7 -documents are enclosed by the standalone -.Sq \&.EQ -and -.Sq \&.EN -tags. -Equations are multi-line blocks consisting of formulas and control -statements. -.Sh EQUATION STRUCTURE -Each equation is bracketed by -.Sq \&.EQ -and -.Sq \&.EN -strings. -.Em Note : -these are not the same as -.Xr roff 7 -macros, and may only be invoked as -.Sq \&.EQ . +An equation starts with an input line containing exactly the characters +.Sq \&.EQ , +may contain multiple input lines, and ends with an input line +containing exactly the characters +.Sq \&.EN . +Equivalently, an equation can be given in the middle of a single +text input line by surrounding it with the equation delimiters +defined with the +.Cm delim +statement. .Pp The equation grammar is as follows, where quoted strings are case-sensitive literals in the input: @@ -178,6 +166,25 @@ statement is a synonym for while .Cm tdefine is discarded. +.It Cm delim +This statement takes a string argument consisting of two bytes, +to be used as the opening and closing delimiters for equations +in the middle of text input lines. +Conventionally, the dollar sign is used for both delimiters, +as follows: +.Bd -literal -offset indent +\&.EQ +delim $$ +\&.EN +An equation like $sin pi = 0$ can now be entered +in the middle of a text input line. +.Ed +.Pp +The special statement +.Cm delim off +temporarily disables previously declared delimiters and +.Cm delim on +reenables them. .It Cm gfont Set the default font of subsequent output. Its syntax is as follows: |