YES Problem: strict: f(0()) -> s(0()) f(s(0())) -> s(0()) f(s(s(x))) -> f(f(s(x))) weak: rand(x) -> x rand(x) -> rand(s(x)) Proof: Arctic Interpretation Processor: dimension: 2 interpretation: [0 5 ] [f](x0) = [-& 0 ]x0, [0 0] [rand](x0) = [3 3]x0, [2] [0] = [6], [0 -&] [s](x0) = [0 -&]x0 orientation: [11] [2] f(0()) = [6 ] >= [2] = s(0()) [7] [2] f(s(0())) = [2] >= [2] = s(0()) [5 -&] [5 -&] f(s(s(x))) = [0 -&]x >= [0 -&]x = f(f(s(x))) [0 0] rand(x) = [3 3]x >= x = x [0 0] [0 -&] rand(x) = [3 3]x >= [3 -&]x = rand(s(x)) problem: strict: f(s(0())) -> s(0()) f(s(s(x))) -> f(f(s(x))) weak: rand(x) -> x rand(x) -> rand(s(x)) Arctic Interpretation Processor: dimension: 2 interpretation: [0 2 ] [f](x0) = [-& 0 ]x0, [1 6 ] [rand](x0) = [-& 1 ]x0, [0 ] [0] = [-&], [0 5 ] [s](x0) = [-& -&]x0 orientation: [0 ] [0 ] f(s(0())) = [-&] >= [-&] = s(0()) [0 5 ] [0 5 ] f(s(s(x))) = [-& -&]x >= [-& -&]x = f(f(s(x))) [1 6 ] rand(x) = [-& 1 ]x >= x = x [1 6 ] [1 6 ] rand(x) = [-& 1 ]x >= [-& -&]x = rand(s(x)) problem: strict: f(s(0())) -> s(0()) f(s(s(x))) -> f(f(s(x))) weak: rand(x) -> rand(s(x)) Arctic Interpretation Processor: dimension: 2 interpretation: [0 0] [f](x0) = [0 0]x0, [0 -&] [rand](x0) = [-& -&]x0, [0 ] [0] = [-&], [0 -&] [s](x0) = [0 4 ]x0 orientation: [0] [0] f(s(0())) = [0] >= [0] = s(0()) [4 8] [0 4] f(s(s(x))) = [4 8]x >= [0 4]x = f(f(s(x))) [0 -&] [0 -&] rand(x) = [-& -&]x >= [-& -&]x = rand(s(x)) problem: strict: f(s(0())) -> s(0()) weak: rand(x) -> rand(s(x)) Arctic Interpretation Processor: dimension: 4 interpretation: [0 0 2 0 ] [2 2 3 -&] [f](x0) = [1 3 1 -&]x0 [3 0 1 0 ] , [0 1 0 0 ] [0 1 0 0 ] [rand](x0) = [-& 2 1 1 ]x0 [-& 0 -& -&] , [0 ] [-&] [0] = [2 ] [0 ], [0 0 -& -&] [-& -& -& -&] [s](x0) = [-& 1 -& -&]x0 [-& 1 0 0 ] orientation: [2] [0 ] [2] [-&] f(s(0())) = [1] >= [-&] = s(0()) [3] [2 ] [0 1 0 0 ] [0 1 0 0 ] [0 1 0 0 ] [0 1 0 0 ] rand(x) = [-& 2 1 1 ]x >= [-& 2 1 1 ]x = rand(s(x)) [-& 0 -& -&] [-& -& -& -&] problem: strict: weak: rand(x) -> rand(s(x)) Qed