YES(?,O(n^1)) We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict Trs: { c(y) -> y , c(c(c(y))) -> c(c(a(y, 0()))) , c(a(a(0(), x), y)) -> a(c(c(c(0()))), y) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) Arguments of following rules are not normal-forms: { c(c(c(y))) -> c(c(a(y, 0()))) } All above mentioned rules can be savely removed. We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict Trs: { c(y) -> y , c(a(a(0(), x), y)) -> a(c(c(c(0()))), y) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) The problem is match-bounded by 1. The enriched problem is compatible with the following automaton. { c_0(2) -> 1 , c_0(3) -> 1 , c_1(5) -> 4 , c_1(6) -> 4 , c_1(6) -> 5 , c_1(7) -> 4 , c_1(7) -> 5 , c_1(7) -> 6 , a_0(2, 2) -> 1 , a_0(2, 2) -> 2 , a_0(2, 3) -> 1 , a_0(2, 3) -> 2 , a_0(3, 2) -> 1 , a_0(3, 2) -> 2 , a_0(3, 3) -> 1 , a_0(3, 3) -> 2 , a_1(4, 2) -> 1 , a_1(4, 3) -> 1 , 0_0() -> 1 , 0_0() -> 3 , 0_1() -> 4 , 0_1() -> 5 , 0_1() -> 6 , 0_1() -> 7 , 2 -> 1 , 3 -> 1 , 5 -> 4 , 6 -> 4 , 6 -> 5 , 7 -> 4 , 7 -> 5 , 7 -> 6 } Hurray, we answered YES(?,O(n^1))