We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict Trs: { p(f(f(x))) -> q(f(g(x))) , p(g(g(x))) -> q(g(f(x))) , q(f(f(x))) -> p(f(g(x))) , q(g(g(x))) -> p(g(f(x))) } Obligation: runtime complexity Answer: YES(O(1),O(1)) The input is overlay and right-linear. Switching to innermost rewriting. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict Trs: { p(f(f(x))) -> q(f(g(x))) , p(g(g(x))) -> q(g(f(x))) , q(f(f(x))) -> p(f(g(x))) , q(g(g(x))) -> p(g(f(x))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) We add the following weak dependency pairs: Strict DPs: { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) , p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) , p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } Strict Trs: { p(f(f(x))) -> q(f(g(x))) , p(g(g(x))) -> q(g(f(x))) , q(f(f(x))) -> p(f(g(x))) , q(g(g(x))) -> p(g(f(x))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) No rule is usable, rules are removed from the input problem. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) , p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) The weightgap principle applies (using the following constant growth matrix-interpretation) The following argument positions are usable: none TcT has computed the following constructor-restricted matrix interpretation. [f](x1) = [0] [2] [g](x1) = [0] [0] [p^#](x1) = [0 2] x1 + [0] [0 2] [0] [c_1](x1) = [0] [0] [q^#](x1) = [0] [0] [c_2](x1) = [0] [0] [c_3](x1) = [0] [0] [c_4](x1) = [0] [0] The order satisfies the following ordering constraints: [p^#(f(f(x)))] = [4] [4] > [0] [0] = [c_1(q^#(f(g(x))))] [p^#(g(g(x)))] = [0] [0] >= [0] [0] = [c_2(q^#(g(f(x))))] [q^#(f(f(x)))] = [0] [0] >= [0] [0] = [c_3(p^#(f(g(x))))] [q^#(g(g(x)))] = [0] [0] >= [0] [0] = [c_4(p^#(g(f(x))))] Further, it can be verified that all rules not oriented are covered by the weightgap condition. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } Weak DPs: { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) We estimate the number of application of {1,2,3} by applications of Pre({1,2,3}) = {}. Here rules are labeled as follows: DPs: { 1: p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , 2: q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , 3: q^#(g(g(x))) -> c_4(p^#(g(f(x)))) , 4: p^#(f(f(x))) -> c_1(q^#(f(g(x)))) } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Weak DPs: { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) , p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { p^#(f(f(x))) -> c_1(q^#(f(g(x)))) , p^#(g(g(x))) -> c_2(q^#(g(f(x)))) , q^#(f(f(x))) -> c_3(p^#(f(g(x)))) , q^#(g(g(x))) -> c_4(p^#(g(f(x)))) } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Rules: Empty Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) Empty rules are trivially bounded Hurray, we answered YES(O(1),O(1))