YES(?,O(n^1)) We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict Trs: { g(x, s(y)) -> g(f(x, y), 0()) , g(0(), f(x, x)) -> x , g(f(x, y), 0()) -> f(g(x, 0()), g(y, 0())) , g(s(x), y) -> g(f(x, y), 0()) } 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. { g_0(2, 2) -> 1 , g_1(2, 4) -> 5 , g_1(2, 4) -> 6 , g_1(3, 4) -> 1 , g_1(4, 4) -> 6 , g_1(11, 4) -> 7 , g_1(12, 4) -> 8 , g_2(2, 9) -> 7 , g_2(2, 10) -> 8 , g_2(4, 10) -> 13 , g_2(9, 10) -> 13 , g_2(10, 10) -> 13 , 0_0() -> 1 , 0_0() -> 2 , 0_1() -> 4 , 0_2() -> 9 , 0_2() -> 10 , f_0(2, 2) -> 1 , f_0(2, 2) -> 2 , f_1(2, 2) -> 3 , f_1(2, 4) -> 1 , f_1(2, 4) -> 2 , f_1(2, 9) -> 11 , f_1(2, 10) -> 12 , f_1(5, 6) -> 1 , f_1(6, 6) -> 5 , f_1(6, 6) -> 6 , f_1(6, 6) -> 7 , f_1(6, 6) -> 8 , f_2(7, 8) -> 1 , f_2(8, 13) -> 5 , f_2(8, 13) -> 6 , f_2(8, 13) -> 7 , f_2(8, 13) -> 8 , s_0(2) -> 1 , s_0(2) -> 2 , 2 -> 1 } Hurray, we answered YES(?,O(n^1))