YES Problem: strict: f(x) -> x g(x) -> x weak: f(x) -> g(x) g(x) -> f(x) Proof: Arctic Interpretation Processor: dimension: 3 interpretation: [1 0 -&] [g](x0) = [-& 1 0 ]x0 [-& -& 1 ] , [1 0 -&] [f](x0) = [-& 1 0 ]x0 [-& -& 1 ] orientation: [1 0 -&] f(x) = [-& 1 0 ]x >= x = x [-& -& 1 ] [1 0 -&] g(x) = [-& 1 0 ]x >= x = x [-& -& 1 ] [1 0 -&] [1 0 -&] f(x) = [-& 1 0 ]x >= [-& 1 0 ]x = g(x) [-& -& 1 ] [-& -& 1 ] [1 0 -&] [1 0 -&] g(x) = [-& 1 0 ]x >= [-& 1 0 ]x = f(x) [-& -& 1 ] [-& -& 1 ] problem: strict: weak: f(x) -> g(x) g(x) -> f(x) Qed