YES Problem: p(p(b(a(x0)),x1),p(x2,x3)) -> p(p(x3,a(x2)),p(b(a(x1)),b(x0))) Proof: DP Processor: DPs: p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(b(a(x1)),b(x0)) p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(x3,a(x2)) p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(p(x3,a(x2)),p(b(a(x1)),b(x0))) TRS: p(p(b(a(x0)),x1),p(x2,x3)) -> p(p(x3,a(x2)),p(b(a(x1)),b(x0))) Usable Rule Processor: DPs: p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(b(a(x1)),b(x0)) p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(x3,a(x2)) p#(p(b(a(x0)),x1),p(x2,x3)) -> p#(p(x3,a(x2)),p(b(a(x1)),b(x0))) TRS: Matrix Interpretation Processor: dim=2 usable rules: interpretation: [p#](x0, x1) = [2 0]x0 + [0 2]x1 + [3], [0 1] [0 0] [p](x0, x1) = [2 0]x0 + [1 1]x1, [0 0] [b](x0) = [1 2]x0, [2 2] [1] [a](x0) = [0 0]x0 + [0] orientation: p#(p(b(a(x0)),x1),p(x2,x3)) = [4 4]x0 + [4 0]x2 + [2 2]x3 + [5] >= [2 4]x0 + [3] = p#(b(a(x1)),b(x0)) p#(p(b(a(x0)),x1),p(x2,x3)) = [4 4]x0 + [4 0]x2 + [2 2]x3 + [5] >= [2 0]x3 + [3] = p#(x3,a(x2)) p#(p(b(a(x0)),x1),p(x2,x3)) = [4 4]x0 + [4 0]x2 + [2 2]x3 + [5] >= [2 4]x0 + [0 2]x3 + [3] = p#(p(x3,a(x2)),p(b(a(x1)),b(x0))) problem: DPs: TRS: Qed