YES Problem: a(x1) -> b(x1) b(b(x1)) -> x1 b(c(c(x1))) -> c(c(b(c(a(x1))))) Proof: String Reversal Processor: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) DP Processor: DPs: a#(x1) -> b#(x1) c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> b#(c(c(x1))) c#(c(b(x1))) -> c#(b(c(c(x1)))) c#(c(b(x1))) -> a#(c(b(c(c(x1))))) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) TDG Processor: DPs: a#(x1) -> b#(x1) c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> b#(c(c(x1))) c#(c(b(x1))) -> c#(b(c(c(x1)))) c#(c(b(x1))) -> a#(c(b(c(c(x1))))) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) graph: c#(c(b(x1))) -> c#(c(x1)) -> c#(c(b(x1))) -> a#(c(b(c(c(x1))))) c#(c(b(x1))) -> c#(c(x1)) -> c#(c(b(x1))) -> c#(b(c(c(x1)))) c#(c(b(x1))) -> c#(c(x1)) -> c#(c(b(x1))) -> b#(c(c(x1))) c#(c(b(x1))) -> c#(c(x1)) -> c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> c#(c(x1)) -> c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> c#(b(c(c(x1)))) -> c#(c(b(x1))) -> a#(c(b(c(c(x1))))) c#(c(b(x1))) -> c#(b(c(c(x1)))) -> c#(c(b(x1))) -> c#(b(c(c(x1)))) c#(c(b(x1))) -> c#(b(c(c(x1)))) -> c#(c(b(x1))) -> b#(c(c(x1))) c#(c(b(x1))) -> c#(b(c(c(x1)))) -> c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> c#(b(c(c(x1)))) -> c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> a#(c(b(c(c(x1))))) c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> c#(b(c(c(x1)))) c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> b#(c(c(x1))) c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> a#(c(b(c(c(x1))))) -> a#(x1) -> b#(x1) SCC Processor: #sccs: 1 #rules: 3 #arcs: 16/36 DPs: c#(c(b(x1))) -> c#(c(x1)) c#(c(b(x1))) -> c#(x1) c#(c(b(x1))) -> c#(b(c(c(x1)))) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) interpretation: [1 0 ] [2] [b](x0) = [0 -&]x0 + [0], [c#](x0) = [0 2]x0 + [0], [1 0 ] [2] [a](x0) = [0 -&]x0 + [1], [-& 0 ] [0] [c](x0) = [0 -&]x0 + [1] orientation: c#(c(b(x1))) = [3 2]x1 + [4] >= [2 0]x1 + [3] = c#(c(x1)) c#(c(b(x1))) = [3 2]x1 + [4] >= [0 2]x1 + [0] = c#(x1) c#(c(b(x1))) = [3 2]x1 + [4] >= [2 0]x1 + [3] = c#(b(c(c(x1)))) [1 0 ] [2] [1 0 ] [2] a(x1) = [0 -&]x1 + [1] >= [0 -&]x1 + [0] = b(x1) [2 1] [3] b(b(x1)) = [1 0]x1 + [2] >= x1 = x1 [1 0 ] [2] [1 0 ] [2] c(c(b(x1))) = [0 -&]x1 + [1] >= [0 -&]x1 + [1] = a(c(b(c(c(x1))))) problem: DPs: c#(c(b(x1))) -> c#(x1) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) Restore Modifier: DPs: c#(c(b(x1))) -> c#(x1) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) EDG Processor: DPs: c#(c(b(x1))) -> c#(x1) TRS: a(x1) -> b(x1) b(b(x1)) -> x1 c(c(b(x1))) -> a(c(b(c(c(x1))))) graph: c#(c(b(x1))) -> c#(x1) -> c#(c(b(x1))) -> c#(x1) Usable Rule Processor: DPs: c#(c(b(x1))) -> c#(x1) TRS: Arctic Interpretation Processor: dimension: 1 usable rules: interpretation: [b](x0) = 1x0 + 13, [c#](x0) = x0, [c](x0) = x0 + 0 orientation: c#(c(b(x1))) = 1x1 + 13 >= x1 = c#(x1) problem: DPs: TRS: Qed