Sch11.15
Premises:
(forall ?X (not (= 0 (succ ?X)))) (forall (?X ?Y) (=> (= (succ ?X) (succ ?Y)) (= ?X ?Y))) (forall ?X (= (+ ?X 0) ?X)) (forall (?X ?Y) (= (+ ?X (succ ?Y)) (succ (+ ?X ?Y))))
Conclusion:
(= (+ (succ (succ 0)) (succ (succ 0))) (succ (succ (succ (succ 0)))))
Proof Trace