;; This domain generalizes the "Seven bridges of Königsberg" problem. (define (domain bridges) (:requirements :strips) (:predicates (IS-LAND-MASS ?lm) (IS-BRIDGE ?b) (CONNECTS ?b ?lm1 ?lm2) (is-current-location ?lm) (bridge-has-been-used ?b) (bridge-has-not-been-used ?b) ) (:action cross-bridge :parameters (?b ?lm1 ?lm2) :precondition (and (IS-BRIDGE ?b) (IS-LAND-MASS ?lm1) (IS-LAND-MASS ?lm2) (CONNECTS ?b ?lm1 ?lm2) (is-current-location ?lm1) (bridge-has-not-been-used ?b) ) :effect (and (bridge-has-been-used ?b) (not (bridge-has-not-been-used ?b)) (not (is-current-location ?lm1)) (is-current-location ?lm2))) )