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