YES Problem: b(c(x1)) -> c(b(x1)) c(b(x1)) -> a(a(a(x1))) a(a(a(a(x1)))) -> b(c(x1)) Proof: DP Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> c#(b(x1)) c#(b(x1)) -> a#(x1) c#(b(x1)) -> a#(a(x1)) c#(b(x1)) -> a#(a(a(x1))) a#(a(a(a(x1)))) -> c#(x1) a#(a(a(a(x1)))) -> b#(c(x1)) TRS: b(c(x1)) -> c(b(x1)) c(b(x1)) -> a(a(a(x1))) a(a(a(a(x1)))) -> b(c(x1)) TDG Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> c#(b(x1)) c#(b(x1)) -> a#(x1) c#(b(x1)) -> a#(a(x1)) c#(b(x1)) -> a#(a(a(x1))) a#(a(a(a(x1)))) -> c#(x1) a#(a(a(a(x1)))) -> b#(c(x1)) TRS: b(c(x1)) -> c(b(x1)) c(b(x1)) -> a(a(a(x1))) a(a(a(a(x1)))) -> b(c(x1)) graph: a#(a(a(a(x1)))) -> c#(x1) -> c#(b(x1)) -> a#(a(a(x1))) a#(a(a(a(x1)))) -> c#(x1) -> c#(b(x1)) -> a#(a(x1)) a#(a(a(a(x1)))) -> c#(x1) -> c#(b(x1)) -> a#(x1) a#(a(a(a(x1)))) -> b#(c(x1)) -> b#(c(x1)) -> c#(b(x1)) a#(a(a(a(x1)))) -> b#(c(x1)) -> b#(c(x1)) -> b#(x1) c#(b(x1)) -> a#(a(a(x1))) -> a#(a(a(a(x1)))) -> b#(c(x1)) c#(b(x1)) -> a#(a(a(x1))) -> a#(a(a(a(x1)))) -> c#(x1) c#(b(x1)) -> a#(a(x1)) -> a#(a(a(a(x1)))) -> b#(c(x1)) c#(b(x1)) -> a#(a(x1)) -> a#(a(a(a(x1)))) -> c#(x1) c#(b(x1)) -> a#(x1) -> a#(a(a(a(x1)))) -> b#(c(x1)) c#(b(x1)) -> a#(x1) -> a#(a(a(a(x1)))) -> c#(x1) b#(c(x1)) -> c#(b(x1)) -> c#(b(x1)) -> a#(a(a(x1))) b#(c(x1)) -> c#(b(x1)) -> c#(b(x1)) -> a#(a(x1)) b#(c(x1)) -> c#(b(x1)) -> c#(b(x1)) -> a#(x1) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> c#(b(x1)) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) Matrix Interpretation Processor: dim=2 interpretation: [a#](x0) = [0 2]x0, [c#](x0) = [1 2]x0 + [1], [b#](x0) = [1 2]x0 + [3], [1 0] [1] [a](x0) = [1 1]x0 + [0], [1 0] [1] [b](x0) = [2 1]x0 + [1], [1 0] [2] [c](x0) = [2 1]x0 + [0] orientation: b#(c(x1)) = [5 2]x1 + [5] >= [1 2]x1 + [3] = b#(x1) b#(c(x1)) = [5 2]x1 + [5] >= [5 2]x1 + [4] = c#(b(x1)) c#(b(x1)) = [5 2]x1 + [4] >= [0 2]x1 = a#(x1) c#(b(x1)) = [5 2]x1 + [4] >= [2 2]x1 = a#(a(x1)) c#(b(x1)) = [5 2]x1 + [4] >= [4 2]x1 + [2] = a#(a(a(x1))) a#(a(a(a(x1)))) = [6 2]x1 + [6] >= [1 2]x1 + [1] = c#(x1) a#(a(a(a(x1)))) = [6 2]x1 + [6] >= [5 2]x1 + [5] = b#(c(x1)) [1 0] [3] [1 0] [3] b(c(x1)) = [4 1]x1 + [5] >= [4 1]x1 + [3] = c(b(x1)) [1 0] [3] [1 0] [3] c(b(x1)) = [4 1]x1 + [3] >= [3 1]x1 + [3] = a(a(a(x1))) [1 0] [4] [1 0] [3] a(a(a(a(x1)))) = [4 1]x1 + [6] >= [4 1]x1 + [5] = b(c(x1)) problem: DPs: TRS: b(c(x1)) -> c(b(x1)) c(b(x1)) -> a(a(a(x1))) a(a(a(a(x1)))) -> b(c(x1)) Qed