dnl @ ../doc/m4.texi:1894: Origin of test dnl @ expected status: 0 dnl @ extra options: dnl @ Copyright (C) 2006, 2007, 2008, 2009 Free Software dnl @ Foundation, Inc. dnl @ This file is free software; the Free Software Foundation dnl @ gives unlimited permission to copy and/or distribute it dnl @ with or without modifications, as long as this notice dnl @ is preserved. define(`exch', `$2, $1') dnl @result{} exch(`arg1', `arg2') dnl @result{}arg2, arg1