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