YES(?,O(n^2)) Problem: h(f(x),y) -> f(g(x,y)) g(x,y) -> h(x,y) Proof: RT Transformation Processor: strict: h(f(x),y) -> f(g(x,y)) g(x,y) -> h(x,y) weak: Matrix Interpretation Processor: dimension: 1 interpretation: [g](x0, x1) = x0 + x1 + 15, [h](x0, x1) = x0 + x1 + 2, [f](x0) = x0 orientation: h(f(x),y) = x + y + 2 >= x + y + 15 = f(g(x,y)) g(x,y) = x + y + 15 >= x + y + 2 = h(x,y) problem: strict: h(f(x),y) -> f(g(x,y)) weak: g(x,y) -> h(x,y) Matrix Interpretation Processor: dimension: 2 interpretation: [1 4] [1 4] [1] [g](x0, x1) = [0 1]x0 + [0 0]x1 + [1], [1 4] [1 4] [0] [h](x0, x1) = [0 1]x0 + [0 0]x1 + [1], [1 2] [1] [f](x0) = [0 1]x0 + [1] orientation: [1 6] [1 4] [5] [1 6] [1 4] [4] h(f(x),y) = [0 1]x + [0 0]y + [2] >= [0 1]x + [0 0]y + [2] = f(g(x,y)) [1 4] [1 4] [1] [1 4] [1 4] [0] g(x,y) = [0 1]x + [0 0]y + [1] >= [0 1]x + [0 0]y + [1] = h(x,y) problem: strict: weak: h(f(x),y) -> f(g(x,y)) g(x,y) -> h(x,y) Qed