YES Problem: a(b(a(x))) -> b(a(b(x))) Proof: DP Processor: DPs: a#(b(a(x))) -> a#(b(x)) TRS: a(b(a(x))) -> b(a(b(x))) Usable Rule Processor: DPs: a#(b(a(x))) -> a#(b(x)) TRS: Arctic Interpretation Processor: dimension: 2 usable rules: interpretation: [a#](x0) = [-4 1 ]x0 + [0], [-& 2 ] [1 ] [b](x0) = [2 1 ]x0 + [-4], [-& -1] [1 ] [a](x0) = [2 3 ]x0 + [-2] orientation: a#(b(a(x))) = [4 5]x + [4] >= [3 2]x + [0] = a#(b(x)) problem: DPs: TRS: Qed