U12 tt s length L zeros cons 0 U11 tt U12 tt length nil 0 length cons N U11 tt U12 1 tt 0 s 1 length 1 zeros 0 cons 1 0 0 U11 1 nil 0 FULL ./TRS/TRCSR/LengthOfFiniteLists_nosorts-noand_L.trs