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