YES Problem: +(x,0()) -> x +(x,s(y)) -> s(+(x,y)) +(0(),s(y)) -> s(y) s(+(0(),y)) -> s(y) Proof: Matrix Interpretation Processor: dim=1 interpretation: [s](x0) = x0 + 6, [+](x0, x1) = x0 + x1 + 5, [0] = 6 orientation: +(x,0()) = x + 11 >= x = x +(x,s(y)) = x + y + 11 >= x + y + 11 = s(+(x,y)) +(0(),s(y)) = y + 17 >= y + 6 = s(y) s(+(0(),y)) = y + 17 >= y + 6 = s(y) problem: +(x,s(y)) -> s(+(x,y)) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [0] [s](x0) = [0 0 0]x0 + [1] [0 1 1] [0], [1 0 0] [1 1 1] [+](x0, x1) = [0 0 0]x0 + [0 1 0]x1 [1 0 0] [0 0 1] orientation: [1 0 0] [1 1 1] [1] [1 0 0] [1 1 1] [0] +(x,s(y)) = [0 0 0]x + [0 0 0]y + [1] >= [0 0 0]x + [0 0 0]y + [1] = s(+(x,y)) [1 0 0] [0 1 1] [0] [1 0 0] [0 1 1] [0] problem: Qed