YES(O(1),O(n^2)) We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^2)). Strict Trs: { p(0()) -> 0() , p(s(x)) -> x , minus(x, 0()) -> x , minus(x, s(y)) -> minus(p(x), y) } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^2)) We add following weak dependency pairs: Strict DPs: { p^#(0()) -> c_1() , p^#(s(x)) -> c_2() , minus^#(x, 0()) -> c_3() , minus^#(x, s(y)) -> c_4(minus^#(p(x), y)) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^2)). Strict DPs: { p^#(0()) -> c_1() , p^#(s(x)) -> c_2() , minus^#(x, 0()) -> c_3() , minus^#(x, s(y)) -> c_4(minus^#(p(x), y)) } Strict Trs: { p(0()) -> 0() , p(s(x)) -> x , minus(x, 0()) -> x , minus(x, s(y)) -> minus(p(x), y) } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^2)) We replace rewrite rules by usable rules: Strict Usable Rules: { p(0()) -> 0() , p(s(x)) -> x } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(n^2)). Strict DPs: { p^#(0()) -> c_1() , p^#(s(x)) -> c_2() , minus^#(x, 0()) -> c_3() , minus^#(x, s(y)) -> c_4(minus^#(p(x), y)) } Strict Trs: { p(0()) -> 0() , p(s(x)) -> x } Obligation: innermost runtime complexity Answer: YES(O(1),O(n^2)) The weightgap principle applies (using the following constant growth matrix-interpretation) The following argument positions are usable: Uargs(minus^#) = {1}, Uargs(c_4) = {1} TcT has computed following constructor-restricted matrix interpretation. [p](x1) = [1] x1 + [2] [0] = [2] [s](x1) = [1] x1 + [1] [p^#](x1) = [1] x1 + [1] [c_1] = [1] [c_2] = [1] [minus^#](x1, x2) = [1] x1 + [2] x2 + [2] [c_3] = [1] [c_4](x1) = [1] x1 + [2] This order satisfies following ordering constraints: [p(0())] = [4] > [2] = [0()] [p(s(x))] = [1] x + [3] > [1] x + [0] = [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^2)). Strict DPs: { minus^#(x, s(y)) -> c_4(minus^#(p(x), y)) } Weak DPs: { p^#(0()) -> c_1() , p^#(s(x)) -> c_2() , minus^#(x, 0()) -> c_3() } Weak Trs: { p(0()) -> 0() , p(s(x)) -> x } Obligation: innermost runtime complexity Answer: YES(?,O(n^2)) The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { p^#(0()) -> c_1() , p^#(s(x)) -> c_2() , minus^#(x, 0()) -> c_3() } We are left with following problem, upon which TcT provides the certificate YES(?,O(n^2)). Strict DPs: { minus^#(x, s(y)) -> c_4(minus^#(p(x), y)) } Weak Trs: { p(0()) -> 0() , p(s(x)) -> x } Obligation: innermost runtime complexity Answer: YES(?,O(n^2)) The input was oriented with the instance of 'Small Polynomial Path Order (PS)' as induced by the safe mapping safe(p) = {1}, safe(0) = {}, safe(s) = {1}, safe(minus^#) = {1}, safe(c_4) = {} and precedence minus^# > p . Following symbols are considered recursive: {p, minus^#} The recursion depth is 2. Further, following argument filtering is employed: pi(p) = 1, pi(0) = [], pi(s) = [1], pi(minus^#) = [1, 2], pi(c_4) = [1] Usable defined function symbols are a subset of: {p, minus^#} For your convenience, here are the satisfied ordering constraints: pi(minus^#(x, s(y))) = minus^#(s(; y); x) > c_4(minus^#(y; x);) = pi(c_4(minus^#(p(x), y))) pi(p(0())) = 0() >= 0() = pi(0()) pi(p(s(x))) = s(; x) > x = pi(x) Hurray, we answered YES(O(1),O(n^2))