Two or More `First' Lines
=========================

  To create two or more `first' or header lines for a definition, follow
the first `@deffn' line by a line beginning with `@deffnx'.  The
`@deffnx' command works exactly like `@deffn' except that it does not
generate extra vertical white space between it and the preceding line.

  For example,

     @deffn {Interactive Command} isearch-forward
     @deffnx {Interactive Command} isearch-backward
     These two search commands are similar except ...
     @end deffn

produces

 - Interactive Command: isearch-forward
 - Interactive Command: isearch-backward
     These two search commands are similar except ...

  Each of the other definition commands has an `x' form: `@defunx',
`@defvrx', `@deftypefunx', etc.

  The `x' forms work just like `@itemx'; see See `@itemx': itemx.