Invoking Macros
===============

  After a macro is defined (see the previous section), you can use
("invoke") it in your document like this:

     @MACRO-NAME {ARG1, ARG2, ...}

and the result will be just as if you typed the body of MACRO-NAME at
that spot.  For example:

     @macro foo {p, q}
     Together: \p\ & \q\.
     @end macro
     @foo{a, b}

produces:

     Together: a & b.

  Thus, the arguments and parameters are separated by commas and
delimited by braces; any whitespace after (but not before) a comma is
ignored.  To insert a comma, brace, or backslash in an argument,
prepend a backslash, as in

     @MACRO-NAME {\\\{\}\,}

which will pass the (almost certainly error-producing) argument `\{},'
to MACRO-NAME.

  If the macro is defined to take a single argument, and is invoked
without any braces, the entire rest of the line after the macro name is
supplied as the argument.  For example:

     @macro bar {p}
     Twice: \p\, \p\.
     @end macro
     @bar aah

produces:

     Twice: aah, aah.