lessElements l t lessE l t 0 lessE l t n if le length l n le length toList t n l t n if true b l t n l if false true l t n t if false false l t n lessE l t s n length nil 0 length cons n l s length l toList leaf nil toList node t1 n t2 append toList t1 cons n toList t2 append nil l2 l2 append cons n l1 l2 cons n append l1 l2 le s n 0 false le 0 m true le s n s m le n m a c a d lessElements 2 lessE 3 0 0 if 5 le 2 length 1 toList 1 true 0 false 0 s 1 nil 0 cons 2 leaf 0 node 3 append 2 a 0 c 0 d 0 FULL ./TRS/secret07/aprove/aprove10.trs