YES Problem: a(b(b(a(a(b(x1)))))) -> a(a(b(b(a(b(a(x1))))))) Proof: DP Processor: DPs: a#(b(b(a(a(b(x1)))))) -> a#(x1) a#(b(b(a(a(b(x1)))))) -> a#(b(a(x1))) a#(b(b(a(a(b(x1)))))) -> a#(b(b(a(b(a(x1)))))) a#(b(b(a(a(b(x1)))))) -> a#(a(b(b(a(b(a(x1))))))) TRS: a(b(b(a(a(b(x1)))))) -> a(a(b(b(a(b(a(x1))))))) Matrix Interpretation Processor: dim=4 interpretation: [a#](x0) = [0 0 0 1]x0, [0 1 1 0] [0] [0 0 0 0] [1] [a](x0) = [0 0 0 0]x0 + [0] [1 0 0 1] [0], [0 0 0 0] [0] [0 0 0 0] [1] [b](x0) = [1 0 0 0]x0 + [0] [0 0 0 1] [0] orientation: a#(b(b(a(a(b(x1)))))) = [1 0 0 1]x1 + [1] >= [0 0 0 1]x1 = a#(x1) a#(b(b(a(a(b(x1)))))) = [1 0 0 1]x1 + [1] >= [1 0 0 1]x1 = a#(b(a(x1))) a#(b(b(a(a(b(x1)))))) = [1 0 0 1]x1 + [1] >= [1 0 0 1]x1 = a#(b(b(a(b(a(x1)))))) a#(b(b(a(a(b(x1)))))) = [1 0 0 1]x1 + [1] >= [1 0 0 1]x1 = a#(a(b(b(a(b(a(x1))))))) [0 0 0 0] [1] [0 0 0 0] [1] [0 0 0 0] [1] [0 0 0 0] [1] a(b(b(a(a(b(x1)))))) = [0 0 0 0]x1 + [0] >= [0 0 0 0]x1 + [0] = a(a(b(b(a(b(a(x1))))))) [1 0 0 1] [1] [1 0 0 1] [1] problem: DPs: TRS: a(b(b(a(a(b(x1)))))) -> a(a(b(b(a(b(a(x1))))))) Qed