YES Problem: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,x) Proof: DP Processor: DPs: f#(s(x),y) -> f#(x,s(x)) f#(x,s(y)) -> f#(y,x) TRS: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,x) Arctic Interpretation Processor: dimension: 1 interpretation: [f#](x0, x1) = 1x0 + x1, [f](x0, x1) = -9x0 + -9x1 + 0, [s](x0) = 1x0 orientation: f#(s(x),y) = 2x + y >= 1x = f#(x,s(x)) f#(x,s(y)) = 1x + 1y >= x + 1y = f#(y,x) f(s(x),y) = -8x + -9y + 0 >= -8x + 0 = f(x,s(x)) f(x,s(y)) = -9x + -8y + 0 >= -9x + -9y + 0 = f(y,x) problem: DPs: f#(x,s(y)) -> f#(y,x) TRS: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,x) Arctic Interpretation Processor: dimension: 1 interpretation: [f#](x0, x1) = 4x0 + x1, [f](x0, x1) = 1x0 + 1x1, [s](x0) = 5x0 orientation: f#(x,s(y)) = 4x + 5y >= x + 4y = f#(y,x) f(s(x),y) = 6x + 1y >= 6x = f(x,s(x)) f(x,s(y)) = 1x + 6y >= 1x + 1y = f(y,x) problem: DPs: TRS: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,x) Qed