YES Problem: f(a(),f(b(),x)) -> f(b(),f(a(),x)) f(b(),f(c(),x)) -> f(c(),f(b(),x)) f(c(),f(a(),x)) -> f(a(),f(c(),x)) Proof: Extended Uncurrying Processor: application symbol: f symbol table: c ==> c0/0 c1/1 b ==> b0/0 b1/1 a ==> a0/0 a1/1 uncurry-rules: f(a0(),x1) -> a1(x1) f(b0(),x3) -> b1(x3) f(c0(),x5) -> c1(x5) eta-rules: problem: a1(b1(x)) -> b1(a1(x)) b1(c1(x)) -> c1(b1(x)) c1(a1(x)) -> a1(c1(x)) f(a0(),x1) -> a1(x1) f(b0(),x3) -> b1(x3) f(c0(),x5) -> c1(x5) Matrix Interpretation Processor: dim=1 interpretation: [a0] = 1, [c0] = 2, [a1](x0) = 2x0 + 2, [b1](x0) = 2x0 + 2, [c1](x0) = 2x0 + 2, [b0] = 1, [f](x0, x1) = x0 + 2x1 + 1 orientation: a1(b1(x)) = 4x + 6 >= 4x + 6 = b1(a1(x)) b1(c1(x)) = 4x + 6 >= 4x + 6 = c1(b1(x)) c1(a1(x)) = 4x + 6 >= 4x + 6 = a1(c1(x)) f(a0(),x1) = 2x1 + 2 >= 2x1 + 2 = a1(x1) f(b0(),x3) = 2x3 + 2 >= 2x3 + 2 = b1(x3) f(c0(),x5) = 2x5 + 3 >= 2x5 + 2 = c1(x5) problem: a1(b1(x)) -> b1(a1(x)) b1(c1(x)) -> c1(b1(x)) c1(a1(x)) -> a1(c1(x)) f(a0(),x1) -> a1(x1) f(b0(),x3) -> b1(x3) Matrix Interpretation Processor: dim=3 interpretation: [0] [a0] = [0] [1], [1 0 1] [0] [a1](x0) = [0 0 0]x0 + [1] [0 1 0] [0], [1 0 1] [0] [b1](x0) = [0 0 0]x0 + [1] [0 1 0] [0], [1 1 1] [0] [c1](x0) = [0 0 0]x0 + [1] [0 0 0] [1], [0] [b0] = [0] [0], [1 0 1] [1 0 1] [0] [f](x0, x1) = [0 0 0]x0 + [1 0 0]x1 + [1] [0 0 0] [1 1 0] [0] orientation: [1 1 1] [0] [1 1 1] [0] a1(b1(x)) = [0 0 0]x + [1] >= [0 0 0]x + [1] = b1(a1(x)) [0 0 0] [1] [0 0 0] [1] [1 1 1] [1] [1 1 1] [1] b1(c1(x)) = [0 0 0]x + [1] >= [0 0 0]x + [1] = c1(b1(x)) [0 0 0] [1] [0 0 0] [1] [1 1 1] [1] [1 1 1] [1] c1(a1(x)) = [0 0 0]x + [1] >= [0 0 0]x + [1] = a1(c1(x)) [0 0 0] [1] [0 0 0] [1] [1 0 1] [1] [1 0 1] [0] f(a0(),x1) = [1 0 0]x1 + [1] >= [0 0 0]x1 + [1] = a1(x1) [1 1 0] [0] [0 1 0] [0] [1 0 1] [0] [1 0 1] [0] f(b0(),x3) = [1 0 0]x3 + [1] >= [0 0 0]x3 + [1] = b1(x3) [1 1 0] [0] [0 1 0] [0] problem: a1(b1(x)) -> b1(a1(x)) b1(c1(x)) -> c1(b1(x)) c1(a1(x)) -> a1(c1(x)) f(b0(),x3) -> b1(x3) Matrix Interpretation Processor: dim=1 interpretation: [a1](x0) = x0 + 1, [b1](x0) = x0, [c1](x0) = x0 + 3, [b0] = 0, [f](x0, x1) = x0 + x1 + 1 orientation: a1(b1(x)) = x + 1 >= x + 1 = b1(a1(x)) b1(c1(x)) = x + 3 >= x + 3 = c1(b1(x)) c1(a1(x)) = x + 4 >= x + 4 = a1(c1(x)) f(b0(),x3) = x3 + 1 >= x3 = b1(x3) problem: a1(b1(x)) -> b1(a1(x)) b1(c1(x)) -> c1(b1(x)) c1(a1(x)) -> a1(c1(x)) Matrix Interpretation Processor: dim=3 interpretation: [1 0 1] [0] [a1](x0) = [0 1 0]x0 + [1] [0 0 1] [0], [1 0 0] [0] [b1](x0) = [0 1 1]x0 + [0] [0 0 1] [1], [c1](x0) = x0 orientation: [1 0 1] [1] [1 0 1] [0] a1(b1(x)) = [0 1 1]x + [1] >= [0 1 1]x + [1] = b1(a1(x)) [0 0 1] [1] [0 0 1] [1] [1 0 0] [0] [1 0 0] [0] b1(c1(x)) = [0 1 1]x + [0] >= [0 1 1]x + [0] = c1(b1(x)) [0 0 1] [1] [0 0 1] [1] [1 0 1] [0] [1 0 1] [0] c1(a1(x)) = [0 1 0]x + [1] >= [0 1 0]x + [1] = a1(c1(x)) [0 0 1] [0] [0 0 1] [0] problem: b1(c1(x)) -> c1(b1(x)) c1(a1(x)) -> a1(c1(x)) Matrix Interpretation Processor: dim=1 interpretation: [a1](x0) = 4x0 + 4, [b1](x0) = 4x0 + 2, [c1](x0) = 4x0 + 4 orientation: b1(c1(x)) = 16x + 18 >= 16x + 12 = c1(b1(x)) c1(a1(x)) = 16x + 20 >= 16x + 20 = a1(c1(x)) problem: c1(a1(x)) -> a1(c1(x)) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [0] [a1](x0) = [0 1 0]x0 + [1] [0 0 0] [0], [1 1 0] [c1](x0) = [0 1 0]x0 [0 0 0] orientation: [1 1 0] [1] [1 1 0] [0] c1(a1(x)) = [0 1 0]x + [1] >= [0 1 0]x + [1] = a1(c1(x)) [0 0 0] [0] [0 0 0] [0] problem: Qed