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