YES Problem: f(s(x),y) -> f(x,s(s(x))) f(x,s(s(y))) -> f(y,x) Proof: DP Processor: DPs: f#(s(x),y) -> f#(x,s(s(x))) f#(x,s(s(y))) -> f#(y,x) TRS: f(s(x),y) -> f(x,s(s(x))) f(x,s(s(y))) -> f(y,x) Arctic Interpretation Processor: dimension: 1 interpretation: [f#](x0, x1) = 4x0 + 1x1, [f](x0, x1) = 4x0 + 1x1 + -16, [s](x0) = 2x0 + 0 orientation: f#(s(x),y) = 6x + 1y + 4 >= 5x + 3 = f#(x,s(s(x))) f#(x,s(s(y))) = 4x + 5y + 3 >= 1x + 4y = f#(y,x) f(s(x),y) = 6x + 1y + 4 >= 5x + 3 = f(x,s(s(x))) f(x,s(s(y))) = 4x + 5y + 3 >= 1x + 4y + -16 = f(y,x) problem: DPs: TRS: f(s(x),y) -> f(x,s(s(x))) f(x,s(s(y))) -> f(y,x) Qed