TIMEOUT We are left with following problem, upon which TcT provides the certificate TIMEOUT. Strict Trs: { isList(nil()) -> tt() , isList(Cons(x, xs)) -> isList(xs) , downfrom(0()) -> nil() , downfrom(s(x)) -> Cons(s(x), downfrom(x)) , f(x) -> cond(isList(downfrom(x)), s(x)) , cond(tt(), x) -> f(x) } Obligation: innermost runtime complexity Answer: TIMEOUT Computation stopped due to timeout after 60.0 seconds. Arrrr..