YES(?,O(n^1)) We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict Trs: { f(X) -> n__f(X) , f(0()) -> cons(0(), n__f(s(0()))) , f(s(0())) -> f(p(s(0()))) , p(s(X)) -> X , activate(X) -> X , activate(n__f(X)) -> f(X) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) The problem is match-bounded by 2. The enriched problem is compatible with the following automaton. { f_0(2) -> 1 , f_1(2) -> 1 , f_1(7) -> 1 , 0_0() -> 1 , 0_0() -> 2 , 0_1() -> 3 , 0_1() -> 6 , 0_1() -> 7 , 0_2() -> 8 , 0_2() -> 11 , cons_0(2, 2) -> 1 , cons_0(2, 2) -> 2 , cons_1(3, 4) -> 1 , cons_2(8, 9) -> 1 , n__f_0(2) -> 1 , n__f_0(2) -> 2 , n__f_1(2) -> 1 , n__f_1(5) -> 4 , n__f_2(2) -> 1 , n__f_2(7) -> 1 , n__f_2(10) -> 9 , s_0(2) -> 1 , s_0(2) -> 2 , s_1(6) -> 5 , s_2(11) -> 10 , p_0(2) -> 1 , p_1(5) -> 7 , activate_0(2) -> 1 , 2 -> 1 , 6 -> 7 } Hurray, we answered YES(?,O(n^1))