MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { g(tt(), x, y) -> g(f(x, y), s(x), s(y)) , f(x, s(y)) -> f(x, y) , f(s(x), y) -> f(x, y) , f(0(), 0()) -> tt() } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..