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