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