(domain BLOCKS) 
(type object) 
(predicate holding) 
(arity holding 1) 
(var holding 1 untyped) 
(predicate handempty) 
(arity handempty 0) 
(predicate on) 
(arity on 2) 
(var on 1 untyped) 
(var on 2 untyped) 
(predicate clear) 
(arity clear 1) 
(var clear 1 untyped) 
(predicate ontable) 
(arity ontable 1) 
(var ontable 1 untyped) 
(action stack) 
(var stack x object) 
(var stack y object) 
(precondition stack (holding x )) 
(precondition stack (clear y )) 
(negative_effect stack (holding x )) 
(negative_effect stack (clear y )) 
(pos_effect stack (clear x )) 
(pos_effect stack (handempty )) 
(pos_effect stack (on x y )) 
(action unstack) 
(var unstack x object) 
(var unstack y object) 
(precondition unstack (on x y )) 
(precondition unstack (clear x )) 
(precondition unstack (handempty )) 
(pos_effect unstack (holding x )) 
(pos_effect unstack (clear y )) 
(negative_effect unstack (clear x )) 
(negative_effect unstack (handempty )) 
(negative_effect unstack (on x y )) 
(action pick-up) 
(var pick-up x object) 
(precondition pick-up (clear x )) 
(precondition pick-up (ontable x )) 
(precondition pick-up (handempty )) 
(negative_effect pick-up (ontable x )) 
(negative_effect pick-up (clear x )) 
(negative_effect pick-up (handempty )) 
(pos_effect pick-up (holding x )) 
(action put-down) 
(var put-down x object) 
(precondition put-down (holding x )) 
(negative_effect put-down (holding x )) 
(pos_effect put-down (clear x )) 
(pos_effect put-down (handempty )) 
(pos_effect put-down (ontable x ))