YES Problem: a__f(a(),X,X) -> a__f(X,a__b(),b()) a__b() -> a() mark(f(X1,X2,X3)) -> a__f(X1,mark(X2),X3) mark(b()) -> a__b() mark(a()) -> a() a__f(X1,X2,X3) -> f(X1,X2,X3) a__b() -> b() Proof: Matrix Interpretation Processor: dim=1 interpretation: [mark](x0) = 2x0, [f](x0, x1, x2) = 2x0 + 2x1 + x2 + 1, [b] = 0, [a__b] = 0, [a__f](x0, x1, x2) = 4x0 + 2x1 + 2x2 + 2, [a] = 0 orientation: a__f(a(),X,X) = 4X + 2 >= 4X + 2 = a__f(X,a__b(),b()) a__b() = 0 >= 0 = a() mark(f(X1,X2,X3)) = 4X1 + 4X2 + 2X3 + 2 >= 4X1 + 4X2 + 2X3 + 2 = a__f(X1,mark(X2),X3) mark(b()) = 0 >= 0 = a__b() mark(a()) = 0 >= 0 = a() a__f(X1,X2,X3) = 4X1 + 2X2 + 2X3 + 2 >= 2X1 + 2X2 + X3 + 1 = f(X1,X2,X3) a__b() = 0 >= 0 = b() problem: a__f(a(),X,X) -> a__f(X,a__b(),b()) a__b() -> a() mark(f(X1,X2,X3)) -> a__f(X1,mark(X2),X3) mark(b()) -> a__b() mark(a()) -> a() a__b() -> b() Matrix Interpretation Processor: dim=1 interpretation: [mark](x0) = x0 + 3, [f](x0, x1, x2) = 3x0 + 4x1 + 4x2 + 6, [b] = 0, [a__b] = 0, [a__f](x0, x1, x2) = x0 + x1 + x2, [a] = 0 orientation: a__f(a(),X,X) = 2X >= X = a__f(X,a__b(),b()) a__b() = 0 >= 0 = a() mark(f(X1,X2,X3)) = 3X1 + 4X2 + 4X3 + 9 >= X1 + X2 + X3 + 3 = a__f(X1,mark(X2),X3) mark(b()) = 3 >= 0 = a__b() mark(a()) = 3 >= 0 = a() a__b() = 0 >= 0 = b() problem: a__f(a(),X,X) -> a__f(X,a__b(),b()) a__b() -> a() a__b() -> b() Matrix Interpretation Processor: dim=3 interpretation: [0] [b] = [0] [0], [1] [a__b] = [0] [1], [1 0 1] [1 0 0] [1 0 1] [a__f](x0, x1, x2) = [1 0 0]x0 + [0 0 0]x1 + [1 0 0]x2 [0 0 0] [0 0 0] [0 0 0] , [0] [a] = [0] [1] orientation: [2 0 1] [1] [1 0 1] [1] a__f(a(),X,X) = [1 0 0]X + [0] >= [1 0 0]X + [0] = a__f(X,a__b(),b()) [0 0 0] [0] [0 0 0] [0] [1] [0] a__b() = [0] >= [0] = a() [1] [1] [1] [0] a__b() = [0] >= [0] = b() [1] [0] problem: a__f(a(),X,X) -> a__f(X,a__b(),b()) Matrix Interpretation Processor: dim=3 interpretation: [0] [b] = [0] [0], [0] [a__b] = [0] [0], [1 0 0] [1 0 0] [1 0 0] [a__f](x0, x1, x2) = [0 0 0]x0 + [0 0 0]x1 + [0 0 0]x2 [0 0 0] [0 0 0] [0 0 0] , [1] [a] = [0] [0] orientation: [2 0 0] [1] [1 0 0] a__f(a(),X,X) = [0 0 0]X + [0] >= [0 0 0]X = a__f(X,a__b(),b()) [0 0 0] [0] [0 0 0] problem: Qed