YES(O(1),O(n^1)) We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^1)). Strict Trs: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) , log(s(0())) -> 0() , log(s(s(x))) -> s(log(s(half(x)))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^1)) We add following weak dependency pairs: Strict DPs: { half^#(0()) -> c_1() , half^#(s(s(x))) -> c_2(half^#(x)) , log^#(s(0())) -> c_3() , log^#(s(s(x))) -> c_4(log^#(s(half(x)))) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^1)). Strict DPs: { half^#(0()) -> c_1() , half^#(s(s(x))) -> c_2(half^#(x)) , log^#(s(0())) -> c_3() , log^#(s(s(x))) -> c_4(log^#(s(half(x)))) } Strict Trs: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) , log(s(0())) -> 0() , log(s(s(x))) -> s(log(s(half(x)))) } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^1)) We replace rewrite rules by usable rules: Strict Usable Rules: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^1)). Strict DPs: { half^#(0()) -> c_1() , half^#(s(s(x))) -> c_2(half^#(x)) , log^#(s(0())) -> c_3() , log^#(s(s(x))) -> c_4(log^#(s(half(x)))) } Strict Trs: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^1)) The weightgap principle applies (using the following constant growth matrix-interpretation) The following argument positions are usable: Uargs(s) = {1}, Uargs(c_2) = {1}, Uargs(log^#) = {1}, Uargs(c_4) = {1} TcT has computed following constructor-restricted matrix interpretation. [half](x1) = [1] x1 + [1] [0] = [0] [s](x1) = [1] x1 + [1] [half^#](x1) = [1] x1 + [2] [c_1] = [1] [c_2](x1) = [1] x1 + [1] [log^#](x1) = [2] x1 + [0] [c_3] = [1] [c_4](x1) = [1] x1 + [2] This order satisfies following ordering constraints: [half(0())] = [1] > [0] = [0()] [half(s(s(x)))] = [1] x + [3] > [1] x + [2] = [s(half(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(n^1)). Strict DPs: { log^#(s(s(x))) -> c_4(log^#(s(half(x)))) } Weak DPs: { half^#(0()) -> c_1() , half^#(s(s(x))) -> c_2(half^#(x)) , log^#(s(0())) -> c_3() } Weak Trs: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { half^#(0()) -> c_1() , half^#(s(s(x))) -> c_2(half^#(x)) , log^#(s(0())) -> c_3() } We are left with following problem, upon which TcT provides the certificate YES(?,O(n^1)). Strict DPs: { log^#(s(s(x))) -> c_4(log^#(s(half(x)))) } Weak Trs: { half(0()) -> 0() , half(s(s(x))) -> s(half(x)) } Obligation: innermost runtime complexity Answer: YES(?,O(n^1)) The input was oriented with the instance of 'Small Polynomial Path Order (PS)' as induced by the safe mapping safe(half) = {}, safe(0) = {}, safe(s) = {1}, safe(log^#) = {}, safe(c_4) = {} and precedence half ~ log^# . Following symbols are considered recursive: {half, log^#} The recursion depth is 1. Further, following argument filtering is employed: pi(half) = 1, pi(0) = [], pi(s) = [1], pi(log^#) = [1], pi(c_4) = [1] Usable defined function symbols are a subset of: {half, log^#} For your convenience, here are the satisfied ordering constraints: pi(log^#(s(s(x)))) = log^#(s(; s(; x));) > c_4(log^#(s(; x););) = pi(c_4(log^#(s(half(x))))) pi(half(0())) = 0() >= 0() = pi(0()) pi(half(s(s(x)))) = s(; s(; x)) > s(; x) = pi(s(half(x))) Hurray, we answered YES(O(1),O(n^1))