forward-application := phrase &
[ CAT #cat,
  ARGS < [CAT [ RESULT [ CAT #cat],
		DIRECTION forward,
		ACTIVE [ CAT #cat2]]],
	 [CAT #cat2]>].

backward-application := phrase &
[ CAT #cat,
  ARGS < [ CAT #cat2],
	 [ CAT [ RESULT [ CAT #cat],
		 DIRECTION backward,
		 ACTIVE [ CAT #cat2]]]>].