YES Problem: f(x,c(y)) -> f(x,s(f(y,y))) f(s(x),y) -> f(x,s(c(y))) Proof: DP Processor: DPs: f#(x,c(y)) -> f#(y,y) f#(x,c(y)) -> f#(x,s(f(y,y))) f#(s(x),y) -> f#(x,s(c(y))) TRS: f(x,c(y)) -> f(x,s(f(y,y))) f(s(x),y) -> f(x,s(c(y))) Matrix Interpretation Processor: dim=2 interpretation: [f#](x0, x1) = [1 0]x0 + [0 1]x1, [2 2] [1] [s](x0) = [0 0]x0 + [0], [3 0] [1] [f](x0, x1) = [0 0]x0 + [2], [0 1] [0] [c](x0) = [1 1]x0 + [1] orientation: f#(x,c(y)) = [1 0]x + [1 1]y + [1] >= [1 1]y = f#(y,y) f#(x,c(y)) = [1 0]x + [1 1]y + [1] >= [1 0]x = f#(x,s(f(y,y))) f#(s(x),y) = [2 2]x + [0 1]y + [1] >= [1 0]x = f#(x,s(c(y))) [3 0] [1] [3 0] [1] f(x,c(y)) = [0 0]x + [2] >= [0 0]x + [2] = f(x,s(f(y,y))) [6 6] [4] [3 0] [1] f(s(x),y) = [0 0]x + [2] >= [0 0]x + [2] = f(x,s(c(y))) problem: DPs: TRS: f(x,c(y)) -> f(x,s(f(y,y))) f(s(x),y) -> f(x,s(c(y))) Qed