YES Problem: double(0()) -> 0() double(s(x)) -> s(s(double(x))) half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) -(x,0()) -> x -(s(x),s(y)) -> -(x,y) if(0(),y,z) -> y if(s(x),y,z) -> z half(double(x)) -> x Proof: Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [if](x0, x1, x2) = [0 0 0]x0 + x1 + x2 [0 0 0] , [1 0 0] [-](x0, x1) = x0 + [0 0 0]x1 [0 0 0] , [1 0 1] [0] [half](x0) = [0 0 1]x0 + [0] [1 0 0] [1], [s](x0) = x0 , [1 0 1] [0] [double](x0) = [0 0 0]x0 + [1] [0 1 0] [0], [0] [0] = [1] [1] orientation: [1] [0] double(0()) = [1] >= [1] = 0() [1] [1] [1 0 1] [0] [1 0 1] [0] double(s(x)) = [0 0 0]x + [1] >= [0 0 0]x + [1] = s(s(double(x))) [0 1 0] [0] [0 1 0] [0] [1] [0] half(0()) = [1] >= [1] = 0() [1] [1] [1] [0] half(s(0())) = [1] >= [1] = 0() [1] [1] [1 0 1] [0] [1 0 1] [0] half(s(s(x))) = [0 0 1]x + [0] >= [0 0 1]x + [0] = s(half(x)) [1 0 0] [1] [1 0 0] [1] -(x,0()) = x >= x = x [1 0 0] [1 0 0] -(s(x),s(y)) = x + [0 0 0]y >= x + [0 0 0]y = -(x,y) [0 0 0] [0 0 0] if(0(),y,z) = y + z >= y = y [1 0 0] if(s(x),y,z) = [0 0 0]x + y + z >= z = z [0 0 0] [1 1 1] [0] half(double(x)) = [0 1 0]x + [0] >= x = x [1 0 1] [1] problem: double(s(x)) -> s(s(double(x))) half(s(s(x))) -> s(half(x)) -(x,0()) -> x -(s(x),s(y)) -> -(x,y) if(0(),y,z) -> y if(s(x),y,z) -> z half(double(x)) -> x Matrix Interpretation Processor: dim=3 interpretation: [1 1 0] [if](x0, x1, x2) = [0 0 0]x0 + x1 + x2 [0 0 0] , [1 0 0] [1 0 1] [-](x0, x1) = [1 1 0]x0 + [0 0 0]x1 [0 0 1] [0 0 0] , [1 0 0] [1] [half](x0) = [0 1 0]x0 + [0] [1 0 1] [0], [1 1 0] [s](x0) = [0 0 0]x0 [0 0 1] , [0] [double](x0) = x0 + [0] [1], [0] [0] = [1] [0] orientation: [1 1 0] [0] [1 1 0] [0] double(s(x)) = [0 0 0]x + [0] >= [0 0 0]x + [0] = s(s(double(x))) [0 0 1] [1] [0 0 1] [1] [1 1 0] [1] [1 1 0] [1] half(s(s(x))) = [0 0 0]x + [0] >= [0 0 0]x + [0] = s(half(x)) [1 1 1] [0] [1 0 1] [0] [1 0 0] -(x,0()) = [1 1 0]x >= x = x [0 0 1] [1 1 0] [1 1 1] [1 0 0] [1 0 1] -(s(x),s(y)) = [1 1 0]x + [0 0 0]y >= [1 1 0]x + [0 0 0]y = -(x,y) [0 0 1] [0 0 0] [0 0 1] [0 0 0] [1] if(0(),y,z) = y + z + [0] >= y = y [0] [1 1 0] if(s(x),y,z) = [0 0 0]x + y + z >= z = z [0 0 0] [1 0 0] [1] half(double(x)) = [0 1 0]x + [0] >= x = x [1 0 1] [1] problem: double(s(x)) -> s(s(double(x))) half(s(s(x))) -> s(half(x)) -(x,0()) -> x -(s(x),s(y)) -> -(x,y) if(s(x),y,z) -> z Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [1 0 0] [if](x0, x1, x2) = [0 1 0]x0 + [0 0 0]x1 + x2 [0 0 0] [0 0 0] , [1 0 0] [1 1 1] [-](x0, x1) = [0 1 1]x0 + [0 0 0]x1 [0 1 1] [1 0 0] , [1 1 0] [half](x0) = [1 1 0]x0 [1 1 0] , [1 0 0] [0] [s](x0) = [0 0 1]x0 + [0] [0 1 0] [1], [1 1 1] [double](x0) = [0 1 1]x0 [0 1 1] , [1] [0] = [0] [0] orientation: [1 1 1] [1] [1 1 1] [0] double(s(x)) = [0 1 1]x + [1] >= [0 1 1]x + [1] = s(s(double(x))) [0 1 1] [1] [0 1 1] [1] [1 1 0] [1] [1 1 0] [0] half(s(s(x))) = [1 1 0]x + [1] >= [1 1 0]x + [0] = s(half(x)) [1 1 0] [1] [1 1 0] [1] [1 0 0] [1] -(x,0()) = [0 1 1]x + [0] >= x = x [0 1 1] [1] [1 0 0] [1 1 1] [1] [1 0 0] [1 1 1] -(s(x),s(y)) = [0 1 1]x + [0 0 0]y + [1] >= [0 1 1]x + [0 0 0]y = -(x,y) [0 1 1] [1 0 0] [1] [0 1 1] [1 0 0] [1 0 0] [1 0 0] if(s(x),y,z) = [0 0 1]x + [0 0 0]y + z >= z = z [0 0 0] [0 0 0] problem: if(s(x),y,z) -> z Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [1 0 0] [if](x0, x1, x2) = [0 0 0]x0 + [0 0 0]x1 + x2 [0 1 0] [0 0 0] , [1 0 0] [1] [s](x0) = [0 0 1]x0 + [0] [0 0 0] [0] orientation: [1 0 0] [1 0 0] [1] if(s(x),y,z) = [0 0 0]x + [0 0 0]y + z + [0] >= z = z [0 0 1] [0 0 0] [0] problem: Qed