((function not
   (signature bvec2
     (parameters
       (declare (in) bvec2 arg0))
     ((return (expression bvec2 ! (var_ref arg0)))))

   (signature bvec3
     (parameters
       (declare (in) bvec3 arg0))
     ((return (expression bvec3 ! (var_ref arg0)))))

   (signature bvec4
     (parameters
       (declare (in) bvec4 arg0))
     ((return (expression bvec4 ! (var_ref arg0)))))
))
