YES Problem: f(s(X),X) -> f(X,a(X)) f(X,c(X)) -> f(s(X),X) f(X,X) -> c(X) Proof: Matrix Interpretation Processor: dim=1 interpretation: [f](x0, x1) = 2x0 + 2x1 + 3, [c](x0) = 4x0, [s](x0) = 4x0, [a](x0) = 4x0 orientation: f(s(X),X) = 10X + 3 >= 10X + 3 = f(X,a(X)) f(X,c(X)) = 10X + 3 >= 10X + 3 = f(s(X),X) f(X,X) = 4X + 3 >= 4X = c(X) problem: f(s(X),X) -> f(X,a(X)) f(X,c(X)) -> f(s(X),X) Matrix Interpretation Processor: dim=1 interpretation: [f](x0, x1) = x0 + x1 + 4, [c](x0) = 7x0 + 1, [s](x0) = 7x0, [a](x0) = 7x0 orientation: f(s(X),X) = 8X + 4 >= 8X + 4 = f(X,a(X)) f(X,c(X)) = 8X + 5 >= 8X + 4 = f(s(X),X) problem: f(s(X),X) -> f(X,a(X)) Matrix Interpretation Processor: dim=1 interpretation: [f](x0, x1) = x0 + 5x1 + 3, [s](x0) = 6x0 + 5, [a](x0) = 2x0 orientation: f(s(X),X) = 11X + 8 >= 11X + 3 = f(X,a(X)) problem: Qed