YES(?,O(n^2)) Problem: g(s(x)) -> f(x) f(0()) -> s(0()) f(s(x)) -> s(s(g(x))) g(0()) -> 0() Proof: Complexity Transformation Processor: strict: g(s(x)) -> f(x) f(0()) -> s(0()) f(s(x)) -> s(s(g(x))) g(0()) -> 0() weak: Matrix Interpretation Processor: dimension: 1 max_matrix: 1 interpretation: [0] = 1, [f](x0) = x0, [g](x0) = x0 + 1, [s](x0) = x0 + 1 orientation: g(s(x)) = x + 2 >= x = f(x) f(0()) = 1 >= 2 = s(0()) f(s(x)) = x + 1 >= x + 3 = s(s(g(x))) g(0()) = 2 >= 1 = 0() problem: strict: f(0()) -> s(0()) f(s(x)) -> s(s(g(x))) weak: g(s(x)) -> f(x) g(0()) -> 0() Matrix Interpretation Processor: dimension: 1 max_matrix: 1 interpretation: [0] = 1, [f](x0) = x0 + 1, [g](x0) = x0 + 1, [s](x0) = x0 orientation: f(0()) = 2 >= 1 = s(0()) f(s(x)) = x + 1 >= x + 1 = s(s(g(x))) g(s(x)) = x + 1 >= x + 1 = f(x) g(0()) = 2 >= 1 = 0() problem: strict: f(s(x)) -> s(s(g(x))) weak: f(0()) -> s(0()) g(s(x)) -> f(x) g(0()) -> 0() Matrix Interpretation Processor: dimension: 2 max_matrix: [1 1] [0 1] interpretation: [1] [0] = [1], [1 1] [0] [f](x0) = [0 1]x0 + [1], [1 1] [g](x0) = [0 1]x0, [0] [s](x0) = x0 + [1] orientation: [1 1] [1] [1 1] [0] f(s(x)) = [0 1]x + [2] >= [0 1]x + [2] = s(s(g(x))) [2] [1] f(0()) = [2] >= [2] = s(0()) [1 1] [1] [1 1] [0] g(s(x)) = [0 1]x + [1] >= [0 1]x + [1] = f(x) [2] [1] g(0()) = [1] >= [1] = 0() problem: strict: weak: f(s(x)) -> s(s(g(x))) f(0()) -> s(0()) g(s(x)) -> f(x) g(0()) -> 0() Qed