active zeros mark cons 0 zeros active U11 tt L mark U12 tt L active U12 tt L mark s length L active length nil mark 0 active length cons N L mark U11 tt L active cons X1 X2 cons active X1 X2 active U11 X1 X2 U11 active X1 X2 active U12 X1 X2 U12 active X1 X2 active s X s active X active length X length active X cons mark X1 X2 mark cons X1 X2 U11 mark X1 X2 mark U11 X1 X2 U12 mark X1 X2 mark U12 X1 X2 s mark X mark s X length mark X mark length X proper zeros ok zeros proper cons X1 X2 cons proper X1 proper X2 proper 0 ok 0 proper U11 X1 X2 U11 proper X1 proper X2 proper tt ok tt proper U12 X1 X2 U12 proper X1 proper X2 proper s X s proper X proper length X length proper X proper nil ok nil cons ok X1 ok X2 ok cons X1 X2 U11 ok X1 ok X2 ok U11 X1 X2 U12 ok X1 ok X2 ok U12 X1 X2 s ok X ok s X length ok X ok length X top mark X top proper X top ok X top active X active 1 zeros 0 mark 1 cons 2 0 0 U11 2 tt 0 U12 2 s 1 length 1 nil 0 proper 1 ok 1 top 1 INNERMOST ./TRS/TRCSR/inn/LengthOfFiniteLists_nosorts_noand_C.trs