dnl @ ../doc/m4.texinfo:3927: Origin of test
dnl @ Copyright (C) 2006 Free Software Foundation
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.
__gnu__
dnl @result{}
ifdef(`__gnu__', `Extensions are active')
dnl @result{}Extensions are active