active zeros mark cons 0 zeros active and tt X mark X active length nil mark 0 active length cons N L mark s length L active take 0 IL mark nil active take s M cons N IL mark cons N take M IL active cons X1 X2 cons active X1 X2 active and X1 X2 and active X1 X2 active length X length active X active s X s active X active take X1 X2 take active X1 X2 active take X1 X2 take X1 active X2 cons mark X1 X2 mark cons X1 X2 and mark X1 X2 mark and X1 X2 length mark X mark length X s mark X mark s X take mark X1 X2 mark take X1 X2 take X1 mark X2 mark take X1 X2 proper zeros ok zeros proper cons X1 X2 cons proper X1 proper X2 proper 0 ok 0 proper and X1 X2 and proper X1 proper X2 proper tt ok tt proper length X length proper X proper nil ok nil proper s X s proper X proper take X1 X2 take proper X1 proper X2 cons ok X1 ok X2 ok cons X1 X2 and ok X1 ok X2 ok and X1 X2 length ok X ok length X s ok X ok s X take ok X1 ok X2 ok take X1 X2 top mark X top proper X top ok X top active X active 1 zeros 0 mark 1 cons 2 0 0 and 2 tt 0 length 1 nil 0 s 1 take 2 proper 1 ok 1 top 1 FULL ./TRS/TRCSR/OvConsOS_nosorts_C.trs