YES Problem: f(0()) -> s(0()) f(s(0())) -> s(0()) f(s(s(x))) -> f(f(s(x))) Proof: Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [s](x0) = [0 1 0]x0 [0 0 0] , [1 0 1] [f](x0) = [0 1 0]x0 [0 0 0] , [0] [0] = [1] [1] orientation: [1] [0] f(0()) = [1] >= [1] = s(0()) [0] [0] [0] [0] f(s(0())) = [1] >= [1] = s(0()) [0] [0] [1 0 0] [1 0 0] f(s(s(x))) = [0 1 0]x >= [0 1 0]x = f(f(s(x))) [0 0 0] [0 0 0] problem: f(s(0())) -> s(0()) f(s(s(x))) -> f(f(s(x))) Matrix Interpretation Processor: dim=3 interpretation: [1 0 1] [0] [s](x0) = [0 0 0]x0 + [1] [0 1 0] [0], [1 0 1] [f](x0) = [0 1 0]x0 [0 1 0] , [0] [0] = [1] [0] orientation: [1] [0] f(s(0())) = [1] >= [1] = s(0()) [1] [1] [1 1 1] [1] [1 1 1] [1] f(s(s(x))) = [0 0 0]x + [1] >= [0 0 0]x + [1] = f(f(s(x))) [0 0 0] [1] [0 0 0] [1] problem: f(s(s(x))) -> f(f(s(x))) Matrix Interpretation Processor: dim=3 interpretation: [1 0 1] [0] [s](x0) = [0 0 0]x0 + [1] [0 1 0] [0], [1 0 1] [f](x0) = [0 0 0]x0 [0 0 0] orientation: [1 1 1] [1] [1 1 1] f(s(s(x))) = [0 0 0]x + [0] >= [0 0 0]x = f(f(s(x))) [0 0 0] [0] [0 0 0] problem: Qed