MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { diff(x, y) -> cond1(equal(x, y), x, y) , cond1(true(), x, y) -> 0() , cond1(false(), x, y) -> cond2(gt(x, y), x, y) , equal(0(), 0()) -> true() , equal(0(), s(y)) -> false() , equal(s(x), 0()) -> false() , equal(s(x), s(y)) -> equal(x, y) , cond2(true(), x, y) -> s(diff(x, s(y))) , cond2(false(), x, y) -> s(diff(s(x), y)) , gt(0(), v) -> false() , gt(s(u), 0()) -> true() , gt(s(u), s(v)) -> gt(u, v) } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..