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) = [0 1 0]x0 + [2], [0 2 0] [a](x0) = [0 0 1]x0 [0 1 0] , [0 2 1] [2] [b](x0) = [0 0 0]x0 + [0] [1 0 0] [0] orientation: a#(a(b(b(x1)))) = [0 2 1]x1 + [4] >= [0 1 0]x1 + [2] = a#(x1) a#(a(b(b(x1)))) = [0 2 1]x1 + [4] >= [0 0 1]x1 + [2] = a#(a(x1)) a#(a(b(b(x1)))) = [0 2 1]x1 + [4] >= [0 1 0]x1 + [2] = a#(a(a(x1))) a#(a(b(b(x1)))) = [0 2 1]x1 + [4] >= [0 0 1]x1 + [2] = a#(a(a(a(x1)))) a#(a(b(b(x1)))) = [0 2 1]x1 + [4] >= [0 1 0]x1 + [2] = a#(a(a(a(a(x1))))) [0 4 2] [4] [0 1 2] [4] a(a(b(b(x1)))) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = b(b(b(a(a(a(a(a(x1)))))))) [0 2 1] [2] [0 2 0] [2] problem: DPs: TRS: a(a(b(b(x1)))) -> b(b(b(a(a(a(a(a(x1)))))))) Qed