MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { f(n__a(), X, X) -> f(activate(X), b(), n__b()) , activate(X) -> X , activate(n__a()) -> a() , activate(n__b()) -> b() , b() -> n__b() , b() -> a() , a() -> n__a() } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..