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: 3 usable rules: a(x1) -> b(x1) b(b(a(x1))) -> c(x1) c(a(x1)) -> a(a(b(c(x1)))) interpretation: [b#](x0) = [-& -& 0 ]x0 + [0], [0 0 0 ] [b](x0) = [0 0 0 ]x0 [-& 0 -&] , [a#](x0) = [-& -& 0 ]x0 + [0], [c#](x0) = [0 0 0]x0 + [0], [0 0 1] [-&] [a](x0) = [0 0 0]x0 + [-&] [0 0 1] [1 ], [0 0 1 ] [c](x0) = [-& -& 0 ]x0 [0 0 1 ] orientation: a#(x1) = [-& -& 0 ]x1 + [0] >= [-& -& 0 ]x1 + [0] = b#(x1) b#(b(a(x1))) = [0 0 0]x1 + [0] >= [0 0 0]x1 + [0] = c#(x1) c#(a(x1)) = [0 0 1]x1 + [1] >= [0 0 0]x1 + [0] = c#(x1) c#(a(x1)) = [0 0 1]x1 + [1] >= [0 0 1]x1 + [0] = b#(c(x1)) c#(a(x1)) = [0 0 1]x1 + [1] >= [-& -& 0 ]x1 + [0] = a#(b(c(x1))) c#(a(x1)) = [0 0 1]x1 + [1] >= [0 0 1]x1 + [1] = a#(a(b(c(x1)))) [0 0 1] [-&] [0 0 0 ] a(x1) = [0 0 0]x1 + [-&] >= [0 0 0 ]x1 = b(x1) [0 0 1] [1 ] [-& 0 -&] [0 0 1] [1] [0 0 1 ] b(b(a(x1))) = [0 0 1]x1 + [1] >= [-& -& 0 ]x1 = c(x1) [0 0 1] [1] [0 0 1 ] [1 1 2] [2] [1 1 2] [2] c(a(x1)) = [0 0 1]x1 + [1] >= [0 0 1]x1 + [1] = a(a(b(c(x1)))) [1 1 2] [2] [1 1 2] [2] problem: 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#(a(b(c(x1)))) TRS: a(x1) -> b(x1) b(b(a(x1))) -> c(x1) c(a(x1)) -> a(a(b(c(x1)))) Restore Modifier: 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#(a(b(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) c#(a(x1)) -> c#(x1) c#(a(x1)) -> 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)) -> c#(x1) c#(a(x1)) -> c#(x1) -> c#(a(x1)) -> b#(c(x1)) c#(a(x1)) -> c#(x1) -> c#(a(x1)) -> a#(a(b(c(x1)))) c#(a(x1)) -> b#(c(x1)) -> b#(b(a(x1))) -> c#(x1) c#(a(x1)) -> a#(a(b(c(x1)))) -> a#(x1) -> b#(x1) b#(b(a(x1))) -> c#(x1) -> c#(a(x1)) -> c#(x1) b#(b(a(x1))) -> c#(x1) -> c#(a(x1)) -> b#(c(x1)) b#(b(a(x1))) -> c#(x1) -> c#(a(x1)) -> a#(a(b(c(x1)))) a#(x1) -> b#(x1) -> b#(b(a(x1))) -> c#(x1) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> b(x1) b(b(a(x1))) -> c(x1) c(a(x1)) -> a(a(b(c(x1)))) interpretation: [b#](x0) = [0 0]x0 + [0], [0 0 ] [b](x0) = [0 -&]x0, [a#](x0) = [0 0]x0 + [0], [c#](x0) = [0 1]x0 + [0], [0 0] [0] [a](x0) = [0 3]x0 + [3], [-& 0 ] [0] [c](x0) = [0 3 ]x0 + [2] orientation: a#(x1) = [0 0]x1 + [0] >= [0 0]x1 + [0] = b#(x1) b#(b(a(x1))) = [0 3]x1 + [3] >= [0 1]x1 + [0] = c#(x1) c#(a(x1)) = [1 4]x1 + [4] >= [0 1]x1 + [0] = c#(x1) c#(a(x1)) = [1 4]x1 + [4] >= [0 3]x1 + [2] = b#(c(x1)) c#(a(x1)) = [1 4]x1 + [4] >= [0 3]x1 + [3] = a#(a(b(c(x1)))) [0 0] [0] [0 0 ] a(x1) = [0 3]x1 + [3] >= [0 -&]x1 = b(x1) [0 3] [3] [-& 0 ] [0] b(b(a(x1))) = [0 3]x1 + [3] >= [0 3 ]x1 + [2] = c(x1) [0 3] [3] [0 3] [3] c(a(x1)) = [3 6]x1 + [6] >= [3 6]x1 + [6] = 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)))) Restore Modifier: 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) SCC Processor: #sccs: 0 #rules: 0 #arcs: 1/4