YES Problem: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) Proof: DP Processor: DPs: p#(a(x0),p(a(b(x1)),x2)) -> p#(a(a(x1)),x2) p#(a(x0),p(a(b(x1)),x2)) -> p#(a(b(a(x2))),p(a(a(x1)),x2)) TRS: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) Matrix Interpretation Processor: dim=2 usable rules: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) interpretation: [p#](x0, x1) = [1 2]x1 + [1], [1 0] [1 0] [0] [p](x0, x1) = [0 0]x0 + [1 1]x1 + [1], [0 0] [0] [b](x0) = [0 1]x0 + [3], [0 1] [1] [a](x0) = [0 0]x0 + [0] orientation: p#(a(x0),p(a(b(x1)),x2)) = [0 1]x1 + [3 2]x2 + [7] >= [1 2]x2 + [1] = p#(a(a(x1)),x2) p#(a(x0),p(a(b(x1)),x2)) = [0 1]x1 + [3 2]x2 + [7] >= [3 2]x2 + [4] = p#(a(b(a(x2))),p(a(a(x1)),x2)) [0 1] [0 1] [1 0] [5] [1 0] [5] p(a(x0),p(a(b(x1)),x2)) = [0 0]x0 + [0 1]x1 + [2 1]x2 + [6] >= [2 1]x2 + [3] = p(a(b(a(x2))),p(a(a(x1)),x2)) problem: DPs: TRS: p(a(x0),p(a(b(x1)),x2)) -> p(a(b(a(x2))),p(a(a(x1)),x2)) Qed