YES Problem: f(f(x)) -> g(x) Proof: Arctic Interpretation Processor: dimension: 2 interpretation: [0 -&] [g](x0) = [-& -&]x0, [0 1] [f](x0) = [0 0]x0 orientation: [1 1] [0 -&] f(f(x)) = [0 1]x >= [-& -&]x = g(x) problem: Qed