YES(?,O(n^1)) Problem: f(g(x,y),f(y,y)) -> f(g(y,x),y) Proof: Matrix Interpretation Processor: dimension: 1 interpretation: [f](x0, x1) = x0 + x1 + 17, [g](x0, x1) = x0 + x1 + 23 orientation: f(g(x,y),f(y,y)) = x + 3y + 57 >= x + 2y + 40 = f(g(y,x),y) problem: Qed