YES Problem: p(m,n,s(r)) -> p(m,r,n) p(m,s(n),0()) -> p(0(),n,m) p(m,0(),0()) -> m Proof: Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [1 0 0] [1 0 0] [p](x0, x1, x2) = [0 1 1]x0 + [0 1 1]x1 + [0 1 1]x2 [0 1 1] [0 1 1] [0 1 1] , [1 0 0] [1] [s](x0) = [0 0 1]x0 + [0] [0 1 0] [0], [0] [0] = [0] [0] orientation: [1 0 0] [1 0 0] [1 0 0] [1] [1 0 0] [1 0 0] [1 0 0] p(m,n,s(r)) = [0 1 1]m + [0 1 1]n + [0 1 1]r + [0] >= [0 1 1]m + [0 1 1]n + [0 1 1]r = p(m,r,n) [0 1 1] [0 1 1] [0 1 1] [0] [0 1 1] [0 1 1] [0 1 1] [1 0 0] [1 0 0] [1] [1 0 0] [1 0 0] p(m,s(n),0()) = [0 1 1]m + [0 1 1]n + [0] >= [0 1 1]m + [0 1 1]n = p(0(),n,m) [0 1 1] [0 1 1] [0] [0 1 1] [0 1 1] [1 0 0] p(m,0(),0()) = [0 1 1]m >= m = m [0 1 1] problem: p(m,0(),0()) -> m Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [1 1 0] [p](x0, x1, x2) = x0 + [0 0 0]x1 + [0 0 0]x2 [0 0 0] [0 0 0] , [0] [0] = [1] [0] orientation: [1] p(m,0(),0()) = m + [0] >= m = m [0] problem: Qed