Problem: F(H(x),y) -> F(H(x),I(I(y))) F(x,G(y)) -> F(I(x),G(y)) I(x) -> x Proof: Church Rosser Transformation Processor (critical pair closing system, Thm 2.11): I(H(x31)) -> H(x31) F(H(x33),G(x32)) -> F(H(x33),I(I(G(x32)))) critical peaks: joinable Matrix Interpretation Processor: dim=2 interpretation: [1 1] [2 0] [0] [F](x0, x1) = [1 0]x0 + [0 0]x1 + [2], [1 0] [1] [G](x0) = [0 0]x0 + [0], [1 0] [3] [H](x0) = [2 0]x0 + [1], [1 2] [I](x0) = [0 2]x0 orientation: [5 0] [5] [1 0] [3] I(H(x31)) = [4 0]x31 + [2] >= [2 0]x31 + [1] = H(x31) [2 0] [3 0] [6] [2 0] [3 0] [6] F(H(x33),G(x32)) = [0 0]x32 + [1 0]x33 + [5] >= [0 0]x32 + [1 0]x33 + [5] = F(H(x33),I(I(G(x32)))) problem: F(H(x33),G(x32)) -> F(H(x33),I(I(G(x32)))) Matrix Interpretation Processor: dim=2 interpretation: [2 0] [2 3] [F](x0, x1) = [0 0]x0 + [2 2]x1, [1 0] [1] [G](x0) = [1 2]x0 + [1], [2 0] [H](x0) = [0 0]x0, [1 1] [I](x0) = [0 0]x0 orientation: [5 6] [4 0] [5] [4 4] [4 0] [4] F(H(x33),G(x32)) = [4 4]x32 + [0 0]x33 + [4] >= [4 4]x32 + [0 0]x33 + [4] = F(H(x33),I(I(G(x32)))) problem: Qed