YES Problem: f(x,f(f(a(),a()),a())) -> f(f(a(),f(a(),a())),x) Proof: DP Processor: DPs: f#(x,f(f(a(),a()),a())) -> f#(a(),f(a(),a())) f#(x,f(f(a(),a()),a())) -> f#(f(a(),f(a(),a())),x) TRS: f(x,f(f(a(),a()),a())) -> f(f(a(),f(a(),a())),x) Usable Rule Processor: DPs: f#(x,f(f(a(),a()),a())) -> f#(a(),f(a(),a())) f#(x,f(f(a(),a()),a())) -> f#(f(a(),f(a(),a())),x) TRS: Arctic Interpretation Processor: dimension: 1 usable rules: interpretation: [f#](x0, x1) = 2x0 + x1 + 0, [f](x0, x1) = 3x0 + x1 + 4, [a] = 0 orientation: f#(x,f(f(a(),a()),a())) = 2x + 7 >= 4 = f#(a(),f(a(),a())) f#(x,f(f(a(),a()),a())) = 2x + 7 >= x + 6 = f#(f(a(),f(a(),a())),x) problem: DPs: TRS: Qed