YES Problem: a(x1) -> b(x1) b(a(b(b(x1)))) -> b(b(b(a(a(x1))))) Proof: String Reversal Processor: a(x1) -> b(x1) b(b(a(b(x1)))) -> a(a(b(b(b(x1))))) DP Processor: DPs: a#(x1) -> b#(x1) b#(b(a(b(x1)))) -> b#(b(x1)) b#(b(a(b(x1)))) -> b#(b(b(x1))) b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) TRS: a(x1) -> b(x1) b(b(a(b(x1)))) -> a(a(b(b(b(x1))))) TDG Processor: DPs: a#(x1) -> b#(x1) b#(b(a(b(x1)))) -> b#(b(x1)) b#(b(a(b(x1)))) -> b#(b(b(x1))) b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) TRS: a(x1) -> b(x1) b(b(a(b(x1)))) -> a(a(b(b(b(x1))))) graph: b#(b(a(b(x1)))) -> b#(b(b(x1))) -> b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) b#(b(a(b(x1)))) -> b#(b(b(x1))) -> b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) b#(b(a(b(x1)))) -> b#(b(b(x1))) -> b#(b(a(b(x1)))) -> b#(b(b(x1))) b#(b(a(b(x1)))) -> b#(b(b(x1))) -> b#(b(a(b(x1)))) -> b#(b(x1)) b#(b(a(b(x1)))) -> b#(b(x1)) -> b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) b#(b(a(b(x1)))) -> b#(b(x1)) -> b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) b#(b(a(b(x1)))) -> b#(b(x1)) -> b#(b(a(b(x1)))) -> b#(b(b(x1))) b#(b(a(b(x1)))) -> b#(b(x1)) -> b#(b(a(b(x1)))) -> b#(b(x1)) b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) -> a#(x1) -> b#(x1) b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) -> a#(x1) -> b#(x1) a#(x1) -> b#(x1) -> b#(b(a(b(x1)))) -> a#(a(b(b(b(x1))))) a#(x1) -> b#(x1) -> b#(b(a(b(x1)))) -> a#(b(b(b(x1)))) a#(x1) -> b#(x1) -> b#(b(a(b(x1)))) -> b#(b(b(x1))) a#(x1) -> b#(x1) -> b#(b(a(b(x1)))) -> b#(b(x1)) Arctic Interpretation Processor: dimension: 2 interpretation: [b#](x0) = [2 0]x0 + [0], [a#](x0) = [3 0]x0 + [0], [0 0] [b](x0) = [0 0]x0, [0 0] [-&] [a](x0) = [2 0]x0 + [3 ] orientation: a#(x1) = [3 0]x1 + [0] >= [2 0]x1 + [0] = b#(x1) b#(b(a(b(x1)))) = [4 4]x1 + [5] >= [2 2]x1 + [0] = b#(b(x1)) b#(b(a(b(x1)))) = [4 4]x1 + [5] >= [2 2]x1 + [0] = b#(b(b(x1))) b#(b(a(b(x1)))) = [4 4]x1 + [5] >= [3 3]x1 + [0] = a#(b(b(b(x1)))) b#(b(a(b(x1)))) = [4 4]x1 + [5] >= [3 3]x1 + [3] = a#(a(b(b(b(x1))))) [0 0] [-&] [0 0] a(x1) = [2 0]x1 + [3 ] >= [0 0]x1 = b(x1) [2 2] [3] [2 2] [3] b(b(a(b(x1)))) = [2 2]x1 + [3] >= [2 2]x1 + [3] = a(a(b(b(b(x1))))) problem: DPs: a#(x1) -> b#(x1) TRS: a(x1) -> b(x1) b(b(a(b(x1)))) -> a(a(b(b(b(x1))))) EDG Processor: DPs: a#(x1) -> b#(x1) TRS: a(x1) -> b(x1) b(b(a(b(x1)))) -> a(a(b(b(b(x1))))) graph: Qed