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