Actions
Actions describe how objects can bring a change of state. Example - (:action pick-up :parameters (?ob1 ?r1) :precondition (and (clear ?ob1) (on-table ?ob1) (arm-empty ?r1)) :effect (and (not (on-table ?ob1))(not (clear ?ob1)) (not (arm-empty ?r1))(holding ?ob1 ?r1)))
Abstraction removes actions that differ only in identity of resource used from an equivalent class. Example - Pick-up_blockA_rob1 and Pick-up_blockA_rob2.