4.5.2 FindRegExp

Syntax: FindRegExp [pattern]
Abbreviation: FX

searches the current document for the given extended regular expression (see Regular Expressions) . The cursor is positioned on the first string matching the expression. The direction and the kind of search are established by the value of the back search and case sensitive search flags. See SearchBack, and CaseSearch.

If the optional argument pattern is not specified, you can enter it on the input line, the default being the last pattern used.