dnl @ ../doc/m4.texi:4817: 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.
ifdef(`changeword', `', `errprint(` skipping: no changeword support
')m4exit(`77')')dnl
define(`a', `errprint(`Hello')')dnl
changeword(`@\([_a-zA-Z0-9]*\)')
dnl @result{}
@a
dnl @result{}errprint(Hello)