YES Problem: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) Proof: DP Processor: DPs: f#(x,f(a(),a())) -> f#(a(),x) f#(x,f(a(),a())) -> f#(f(a(),a()),a()) f#(x,f(a(),a())) -> f#(f(f(a(),a()),a()),f(a(),x)) TRS: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) CDG Processor: DPs: f#(x,f(a(),a())) -> f#(a(),x) f#(x,f(a(),a())) -> f#(f(a(),a()),a()) f#(x,f(a(),a())) -> f#(f(f(a(),a()),a()),f(a(),x)) TRS: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) graph: f#(x,f(a(),a())) -> f#(a(),x) -> f#(x,f(a(),a())) -> f#(a(),x) f#(x,f(a(),a())) -> f#(a(),x) -> f#(x,f(a(),a())) -> f#(f(a(),a()),a()) f#(x,f(a(),a())) -> f#(a(),x) -> f#(x,f(a(),a())) -> f#(f(f(a(),a()),a()),f(a(),x)) Restore Modifier: DPs: f#(x,f(a(),a())) -> f#(a(),x) f#(x,f(a(),a())) -> f#(f(a(),a()),a()) f#(x,f(a(),a())) -> f#(f(f(a(),a()),a()),f(a(),x)) TRS: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) SCC Processor: #sccs: 1 #rules: 1 #arcs: 3/9 DPs: f#(x,f(a(),a())) -> f#(a(),x) TRS: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) Matrix Interpretation Processor: dimension: 1 interpretation: [f#](x0, x1) = x0 + x1, [f](x0, x1) = 1, [a] = 0 orientation: f#(x,f(a(),a())) = x + 1 >= x = f#(a(),x) f(x,f(a(),a())) = 1 >= 1 = f(f(f(a(),a()),a()),f(a(),x)) problem: DPs: TRS: f(x,f(a(),a())) -> f(f(f(a(),a()),a()),f(a(),x)) Qed