command -> command_name_NCName '(' [ argument ]* ')' ';'

argument -> XPath_expression | XML_template

Invokes command called command_name_NCName with specified arguments.

Predefined commands are documented in Chapter 2, Predefined commands. A user may define her own commands using macro.

Examples:

set-variable("next", 
              following-sibling::node()[1][self::text() and 
                                           starts-with(., "
")]);
delete-text("^\n", "", $next);

replace(<g:envelope>{translate(., "&#xA0;", " ")}</g:envelope>);

unwrap-element();