YES(?,O(n^1)) We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict Trs: { f(X) -> if(X, c(), n__f(true())) , f(X) -> n__f(X) , if(true(), X, Y) -> X , if(false(), X, Y) -> activate(Y) , activate(X) -> X , activate(n__f(X)) -> f(X) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) The problem is match-bounded by 3. The enriched problem is compatible with the following automaton. { f_0(2) -> 1 , f_1(2) -> 1 , f_2(5) -> 1 , f_2(8) -> 1 , if_0(2, 2, 2) -> 1 , if_1(2, 3, 4) -> 1 , if_2(2, 6, 7) -> 1 , if_3(5, 9, 10) -> 1 , if_3(8, 9, 10) -> 1 , c_0() -> 1 , c_0() -> 2 , c_1() -> 1 , c_1() -> 3 , c_2() -> 1 , c_2() -> 6 , c_3() -> 1 , c_3() -> 9 , n__f_0(2) -> 1 , n__f_0(2) -> 2 , n__f_1(2) -> 1 , n__f_1(5) -> 1 , n__f_1(5) -> 4 , n__f_2(2) -> 1 , n__f_2(8) -> 1 , n__f_2(8) -> 7 , n__f_3(5) -> 1 , n__f_3(8) -> 1 , n__f_3(11) -> 10 , true_0() -> 1 , true_0() -> 2 , true_1() -> 5 , true_2() -> 8 , true_3() -> 11 , false_0() -> 1 , false_0() -> 2 , activate_0(2) -> 1 , activate_1(2) -> 1 , activate_1(4) -> 1 , activate_1(7) -> 1 , 2 -> 1 , 3 -> 1 , 4 -> 1 , 6 -> 1 , 7 -> 1 , 9 -> 1 } Hurray, we answered YES(?,O(n^1))