MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { f(empty(), l) -> l , f(cons(x, k), l) -> g(k, l, cons(x, k)) , g(a, b, c) -> f(a, cons(b, c)) } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..