(define (domain blocksworld) (:requirements :strips :typing) (:types block) (:predicates (on ?x - block ?y - block) (ontable ?x - block) (clear ?x - block) (handempty) (holding ?x - block) ) (:action pick-up :parameters (?x - block) :precondition (and (clear ?x) (ontable ?x) (handempty)) :effect (and (not (ontable ?x)) (not (clear ?x)) (not (handempty)) (holding ?x))) (:action put-down :parameters (?x - block) :precondition (holding ?x) :effect (and (not (holding ?x)) (clear ?x) (handempty) (ontable ?x))) (:action stack :parameters (?x - block ?y - block) :precondition (and (holding ?x) (clear ?y)) :effect (and (not (holding ?x)) (not (clear ?y)) (clear ?x) (handempty) (on ?x ?y))) (:action unstack :parameters (?x - block ?y - block) :precondition (and (on ?x ?y) (clear ?x) (handempty)) :effect (and (holding ?x) (clear ?y) (not (clear ?x)) (not (handempty)) (not (on ?x ?y)))) )