YES Problem: a(b(a(x1))) -> b(b(b(a(x1)))) b(b(b(a(x1)))) -> a(a(a(b(x1)))) Proof: DP Processor: DPs: a#(b(a(x1))) -> b#(b(a(x1))) a#(b(a(x1))) -> b#(b(b(a(x1)))) b#(b(b(a(x1)))) -> b#(x1) b#(b(b(a(x1)))) -> a#(b(x1)) b#(b(b(a(x1)))) -> a#(a(b(x1))) b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) TRS: a(b(a(x1))) -> b(b(b(a(x1)))) b(b(b(a(x1)))) -> a(a(a(b(x1)))) TDG Processor: DPs: a#(b(a(x1))) -> b#(b(a(x1))) a#(b(a(x1))) -> b#(b(b(a(x1)))) b#(b(b(a(x1)))) -> b#(x1) b#(b(b(a(x1)))) -> a#(b(x1)) b#(b(b(a(x1)))) -> a#(a(b(x1))) b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) TRS: a(b(a(x1))) -> b(b(b(a(x1)))) b(b(b(a(x1)))) -> a(a(a(b(x1)))) graph: b#(b(b(a(x1)))) -> b#(x1) -> b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) b#(b(b(a(x1)))) -> b#(x1) -> b#(b(b(a(x1)))) -> a#(a(b(x1))) b#(b(b(a(x1)))) -> b#(x1) -> b#(b(b(a(x1)))) -> a#(b(x1)) b#(b(b(a(x1)))) -> b#(x1) -> b#(b(b(a(x1)))) -> b#(x1) b#(b(b(a(x1)))) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(b(b(a(x1)))) b#(b(b(a(x1)))) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(b(a(x1))) b#(b(b(a(x1)))) -> a#(a(b(x1))) -> a#(b(a(x1))) -> b#(b(b(a(x1)))) b#(b(b(a(x1)))) -> a#(a(b(x1))) -> a#(b(a(x1))) -> b#(b(a(x1))) b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) -> a#(b(a(x1))) -> b#(b(b(a(x1)))) b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) -> a#(b(a(x1))) -> b#(b(a(x1))) a#(b(a(x1))) -> b#(b(b(a(x1)))) -> b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) a#(b(a(x1))) -> b#(b(b(a(x1)))) -> b#(b(b(a(x1)))) -> a#(a(b(x1))) a#(b(a(x1))) -> b#(b(b(a(x1)))) -> b#(b(b(a(x1)))) -> a#(b(x1)) a#(b(a(x1))) -> b#(b(b(a(x1)))) -> b#(b(b(a(x1)))) -> b#(x1) a#(b(a(x1))) -> b#(b(a(x1))) -> b#(b(b(a(x1)))) -> a#(a(a(b(x1)))) a#(b(a(x1))) -> b#(b(a(x1))) -> b#(b(b(a(x1)))) -> a#(a(b(x1))) a#(b(a(x1))) -> b#(b(a(x1))) -> b#(b(b(a(x1)))) -> a#(b(x1)) a#(b(a(x1))) -> b#(b(a(x1))) -> b#(b(b(a(x1)))) -> b#(x1) Matrix Interpretation Processor: dim=5 interpretation: [b#](x0) = [0 0 1 0 0]x0, [a#](x0) = [0 0 0 1 0]x0 + [1], [0 0 1 0 0] [0 0 1 0 0] [b](x0) = [0 0 0 1 0]x0 [1 1 0 0 1] [0 0 1 0 0] , [0 1 0 1 0] [0] [0 0 1 1 1] [1] [a](x0) = [0 0 0 0 0]x0 + [0] [0 0 0 0 0] [0] [1 0 0 1 0] [1] orientation: a#(b(a(x1))) = [1 1 1 3 1]x1 + [3] >= [0] = b#(b(a(x1))) a#(b(a(x1))) = [1 1 1 3 1]x1 + [3] >= [1 1 1 3 1]x1 + [2] = b#(b(b(a(x1)))) b#(b(b(a(x1)))) = [1 1 1 3 1]x1 + [2] >= [0 0 1 0 0]x1 = b#(x1) b#(b(b(a(x1)))) = [1 1 1 3 1]x1 + [2] >= [1 1 0 0 1]x1 + [1] = a#(b(x1)) b#(b(b(a(x1)))) = [1 1 1 3 1]x1 + [2] >= [1] = a#(a(b(x1))) b#(b(b(a(x1)))) = [1 1 1 3 1]x1 + [2] >= [1] = a#(a(a(b(x1)))) [1 1 1 3 1] [2] [1 1 1 3 1] [2] [1 1 1 3 1] [3] [1 1 1 3 1] [2] a(b(a(x1))) = [0 0 0 0 0]x1 + [0] >= [0 0 0 0 0]x1 + [0] = b(b(b(a(x1)))) [0 0 0 0 0] [0] [0 0 0 0 0] [0] [1 1 1 3 1] [3] [1 1 1 3 1] [2] [1 1 1 3 1] [2] [1 1 1 0 1] [2] [1 1 1 3 1] [2] [1 1 1 0 1] [2] b(b(b(a(x1)))) = [0 0 0 0 0]x1 + [0] >= [0 0 0 0 0]x1 + [0] = a(a(a(b(x1)))) [0 0 0 0 0] [0] [0 0 0 0 0] [0] [1 1 1 3 1] [2] [1 1 1 1 1] [2] problem: DPs: TRS: a(b(a(x1))) -> b(b(b(a(x1)))) b(b(b(a(x1)))) -> a(a(a(b(x1)))) Qed