YES Problem: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) Proof: DP Processor: DPs: b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> b#(c(x1)) b#(a(a(x1))) -> a#(b(c(x1))) c#(a(x1)) -> c#(x1) c#(a(x1)) -> a#(c(x1)) c#(b(x1)) -> a#(x1) c#(b(x1)) -> b#(a(x1)) a#(a(b(x1))) -> a#(x1) a#(a(b(x1))) -> b#(a(x1)) a#(d(x1)) -> a#(x1) b#(d(x1)) -> b#(x1) b#(d(x1)) -> a#(b(x1)) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) TDG Processor: DPs: b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> b#(c(x1)) b#(a(a(x1))) -> a#(b(c(x1))) c#(a(x1)) -> c#(x1) c#(a(x1)) -> a#(c(x1)) c#(b(x1)) -> a#(x1) c#(b(x1)) -> b#(a(x1)) a#(a(b(x1))) -> a#(x1) a#(a(b(x1))) -> b#(a(x1)) a#(d(x1)) -> a#(x1) b#(d(x1)) -> b#(x1) b#(d(x1)) -> a#(b(x1)) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) graph: a#(d(x1)) -> a#(x1) -> a#(a(x1)) -> a#(b(a(x1))) a#(d(x1)) -> a#(x1) -> a#(a(x1)) -> b#(a(x1)) a#(d(x1)) -> a#(x1) -> a#(d(x1)) -> a#(x1) a#(d(x1)) -> a#(x1) -> a#(a(b(x1))) -> b#(a(x1)) a#(d(x1)) -> a#(x1) -> a#(a(b(x1))) -> a#(x1) a#(a(b(x1))) -> a#(x1) -> a#(a(x1)) -> a#(b(a(x1))) a#(a(b(x1))) -> a#(x1) -> a#(a(x1)) -> b#(a(x1)) a#(a(b(x1))) -> a#(x1) -> a#(d(x1)) -> a#(x1) a#(a(b(x1))) -> a#(x1) -> a#(a(b(x1))) -> b#(a(x1)) a#(a(b(x1))) -> a#(x1) -> a#(a(b(x1))) -> a#(x1) a#(a(b(x1))) -> b#(a(x1)) -> b#(d(x1)) -> a#(b(x1)) a#(a(b(x1))) -> b#(a(x1)) -> b#(d(x1)) -> b#(x1) a#(a(b(x1))) -> b#(a(x1)) -> b#(a(a(x1))) -> a#(b(c(x1))) a#(a(b(x1))) -> b#(a(x1)) -> b#(a(a(x1))) -> b#(c(x1)) a#(a(b(x1))) -> b#(a(x1)) -> b#(a(a(x1))) -> c#(x1) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(x1)) -> a#(b(a(x1))) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) -> a#(d(x1)) -> a#(x1) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(b(x1))) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(b(x1))) -> a#(x1) a#(a(x1)) -> b#(a(x1)) -> b#(d(x1)) -> a#(b(x1)) a#(a(x1)) -> b#(a(x1)) -> b#(d(x1)) -> b#(x1) a#(a(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> a#(b(c(x1))) a#(a(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> b#(c(x1)) a#(a(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> c#(x1) c#(b(x1)) -> a#(x1) -> a#(a(x1)) -> a#(b(a(x1))) c#(b(x1)) -> a#(x1) -> a#(a(x1)) -> b#(a(x1)) c#(b(x1)) -> a#(x1) -> a#(d(x1)) -> a#(x1) c#(b(x1)) -> a#(x1) -> a#(a(b(x1))) -> b#(a(x1)) c#(b(x1)) -> a#(x1) -> a#(a(b(x1))) -> a#(x1) c#(b(x1)) -> b#(a(x1)) -> b#(d(x1)) -> a#(b(x1)) c#(b(x1)) -> b#(a(x1)) -> b#(d(x1)) -> b#(x1) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> a#(b(c(x1))) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> b#(c(x1)) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> c#(x1) c#(a(x1)) -> a#(c(x1)) -> a#(a(x1)) -> a#(b(a(x1))) c#(a(x1)) -> a#(c(x1)) -> a#(a(x1)) -> b#(a(x1)) c#(a(x1)) -> a#(c(x1)) -> a#(d(x1)) -> a#(x1) c#(a(x1)) -> a#(c(x1)) -> a#(a(b(x1))) -> b#(a(x1)) c#(a(x1)) -> a#(c(x1)) -> a#(a(b(x1))) -> a#(x1) c#(a(x1)) -> c#(x1) -> c#(b(x1)) -> b#(a(x1)) c#(a(x1)) -> c#(x1) -> c#(b(x1)) -> a#(x1) c#(a(x1)) -> c#(x1) -> c#(a(x1)) -> a#(c(x1)) c#(a(x1)) -> c#(x1) -> c#(a(x1)) -> c#(x1) b#(d(x1)) -> a#(b(x1)) -> a#(a(x1)) -> a#(b(a(x1))) b#(d(x1)) -> a#(b(x1)) -> a#(a(x1)) -> b#(a(x1)) b#(d(x1)) -> a#(b(x1)) -> a#(d(x1)) -> a#(x1) b#(d(x1)) -> a#(b(x1)) -> a#(a(b(x1))) -> b#(a(x1)) b#(d(x1)) -> a#(b(x1)) -> a#(a(b(x1))) -> a#(x1) b#(d(x1)) -> b#(x1) -> b#(d(x1)) -> a#(b(x1)) b#(d(x1)) -> b#(x1) -> b#(d(x1)) -> b#(x1) b#(d(x1)) -> b#(x1) -> b#(a(a(x1))) -> a#(b(c(x1))) b#(d(x1)) -> b#(x1) -> b#(a(a(x1))) -> b#(c(x1)) b#(d(x1)) -> b#(x1) -> b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> a#(b(c(x1))) -> a#(a(x1)) -> a#(b(a(x1))) b#(a(a(x1))) -> a#(b(c(x1))) -> a#(a(x1)) -> b#(a(x1)) b#(a(a(x1))) -> a#(b(c(x1))) -> a#(d(x1)) -> a#(x1) b#(a(a(x1))) -> a#(b(c(x1))) -> a#(a(b(x1))) -> b#(a(x1)) b#(a(a(x1))) -> a#(b(c(x1))) -> a#(a(b(x1))) -> a#(x1) b#(a(a(x1))) -> c#(x1) -> c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> c#(x1) -> c#(b(x1)) -> a#(x1) b#(a(a(x1))) -> c#(x1) -> c#(a(x1)) -> a#(c(x1)) b#(a(a(x1))) -> c#(x1) -> c#(a(x1)) -> c#(x1) b#(a(a(x1))) -> b#(c(x1)) -> b#(d(x1)) -> a#(b(x1)) b#(a(a(x1))) -> b#(c(x1)) -> b#(d(x1)) -> b#(x1) b#(a(a(x1))) -> b#(c(x1)) -> b#(a(a(x1))) -> a#(b(c(x1))) b#(a(a(x1))) -> b#(c(x1)) -> b#(a(a(x1))) -> b#(c(x1)) b#(a(a(x1))) -> b#(c(x1)) -> b#(a(a(x1))) -> c#(x1) Arctic Interpretation Processor: dimension: 1 usable rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) interpretation: [b#](x0) = x0, [b](x0) = x0, [d](x0) = 2x0, [c#](x0) = 2x0, [a](x0) = 2x0, [a#](x0) = x0, [c](x0) = 2x0 orientation: b#(a(a(x1))) = 4x1 >= 2x1 = c#(x1) b#(a(a(x1))) = 4x1 >= 2x1 = b#(c(x1)) b#(a(a(x1))) = 4x1 >= 2x1 = a#(b(c(x1))) c#(a(x1)) = 4x1 >= 2x1 = c#(x1) c#(a(x1)) = 4x1 >= 2x1 = a#(c(x1)) c#(b(x1)) = 2x1 >= x1 = a#(x1) c#(b(x1)) = 2x1 >= 2x1 = b#(a(x1)) a#(a(b(x1))) = 2x1 >= x1 = a#(x1) a#(a(b(x1))) = 2x1 >= 2x1 = b#(a(x1)) a#(d(x1)) = 2x1 >= x1 = a#(x1) b#(d(x1)) = 2x1 >= x1 = b#(x1) b#(d(x1)) = 2x1 >= x1 = a#(b(x1)) a#(a(x1)) = 2x1 >= 2x1 = b#(a(x1)) a#(a(x1)) = 2x1 >= 2x1 = a#(b(a(x1))) b(a(a(x1))) = 4x1 >= 4x1 = a(b(c(x1))) c(a(x1)) = 4x1 >= 4x1 = a(c(x1)) c(b(x1)) = 2x1 >= 2x1 = b(a(x1)) a(a(b(x1))) = 4x1 >= 4x1 = d(b(a(x1))) a(d(x1)) = 4x1 >= 4x1 = d(a(x1)) b(d(x1)) = 2x1 >= 2x1 = a(b(x1)) a(a(x1)) = 4x1 >= 4x1 = a(b(a(x1))) problem: DPs: c#(b(x1)) -> b#(a(x1)) a#(a(b(x1))) -> b#(a(x1)) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) Restore Modifier: DPs: c#(b(x1)) -> b#(a(x1)) a#(a(b(x1))) -> b#(a(x1)) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) EDG Processor: DPs: c#(b(x1)) -> b#(a(x1)) a#(a(b(x1))) -> b#(a(x1)) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) graph: a#(a(x1)) -> a#(b(a(x1))) -> a#(a(b(x1))) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> a#(b(a(x1))) -> a#(a(x1)) -> a#(b(a(x1))) SCC Processor: #sccs: 1 #rules: 1 #arcs: 3/16 DPs: a#(a(x1)) -> a#(b(a(x1))) TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) Arctic Interpretation Processor: dimension: 1 usable rules: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) interpretation: [b](x0) = -5x0 + 2, [d](x0) = 8x0 + 15, [a](x0) = 8x0 + 8, [a#](x0) = x0 + 0, [c](x0) = 8x0 + -5 orientation: a#(a(x1)) = 8x1 + 8 >= 3x1 + 3 = a#(b(a(x1))) b(a(a(x1))) = 11x1 + 11 >= 11x1 + 10 = a(b(c(x1))) c(a(x1)) = 16x1 + 16 >= 16x1 + 8 = a(c(x1)) c(b(x1)) = 3x1 + 10 >= 3x1 + 3 = b(a(x1)) a(a(b(x1))) = 11x1 + 18 >= 11x1 + 15 = d(b(a(x1))) a(d(x1)) = 16x1 + 23 >= 16x1 + 16 = d(a(x1)) b(d(x1)) = 3x1 + 10 >= 3x1 + 10 = a(b(x1)) a(a(x1)) = 16x1 + 16 >= 11x1 + 11 = a(b(a(x1))) problem: DPs: TRS: b(a(a(x1))) -> a(b(c(x1))) c(a(x1)) -> a(c(x1)) c(b(x1)) -> b(a(x1)) a(a(b(x1))) -> d(b(a(x1))) a(d(x1)) -> d(a(x1)) b(d(x1)) -> a(b(x1)) a(a(x1)) -> a(b(a(x1))) Qed