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