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