WORST_CASE(?,O(n^1)) Solution: --------- "cons" :: ["a"(0) x "b"(1)] -(1)-> "b"(1) "cons" :: ["a"(0) x "b"(0)] -(0)-> "b"(0) "empty" :: [] -(0)-> "b"(1) "empty" :: [] -(0)-> "b"(0) "r1" :: ["b"(1) x "b"(0)] -(1)-> "b"(0) "rev" :: ["b"(1)] -(2)-> "b"(0) Cost Free Signatures: ---------------------