YES Problem: +(0(),y) -> y +(s(x),0()) -> s(x) +(s(x),s(y)) -> s(+(s(x),+(y,0()))) Proof: Matrix Interpretation Processor: dim=1 interpretation: [s](x0) = x0 + 1, [+](x0, x1) = x0 + 2x1, [0] = 0 orientation: +(0(),y) = 2y >= y = y +(s(x),0()) = x + 1 >= x + 1 = s(x) +(s(x),s(y)) = x + 2y + 3 >= x + 2y + 2 = s(+(s(x),+(y,0()))) problem: +(0(),y) -> y +(s(x),0()) -> s(x) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [0] [s](x0) = [0 0 0]x0 + [1] [0 0 0] [1], [1 0 0] [1 1 1] [1] [+](x0, x1) = [0 0 0]x0 + [1 1 1]x1 + [1] [0 0 0] [1 1 1] [1], [0] [0] = [0] [0] orientation: [1 1 1] [1] +(0(),y) = [1 1 1]y + [1] >= y = y [1 1 1] [1] [1 0 0] [1] [1 0 0] [0] +(s(x),0()) = [0 0 0]x + [1] >= [0 0 0]x + [1] = s(x) [0 0 0] [1] [0 0 0] [1] problem: Qed