YES Problem: c(c(c(a(x1)))) -> d(d(x1)) d(b(x1)) -> c(c(x1)) b(c(x1)) -> b(a(c(x1))) c(x1) -> a(a(x1)) d(x1) -> b(c(x1)) Proof: Matrix Interpretation Processor: dim=1 interpretation: [c](x0) = x0 + 2, [b](x0) = x0 + 1, [a](x0) = x0, [d](x0) = x0 + 3 orientation: c(c(c(a(x1)))) = x1 + 6 >= x1 + 6 = d(d(x1)) d(b(x1)) = x1 + 4 >= x1 + 4 = c(c(x1)) b(c(x1)) = x1 + 3 >= x1 + 3 = b(a(c(x1))) c(x1) = x1 + 2 >= x1 = a(a(x1)) d(x1) = x1 + 3 >= x1 + 3 = b(c(x1)) problem: c(c(c(a(x1)))) -> d(d(x1)) d(b(x1)) -> c(c(x1)) b(c(x1)) -> b(a(c(x1))) d(x1) -> b(c(x1)) String Reversal Processor: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) DP Processor: DPs: a#(c(c(c(x1)))) -> d#(x1) a#(c(c(c(x1)))) -> d#(d(x1)) b#(d(x1)) -> c#(x1) b#(d(x1)) -> c#(c(x1)) c#(b(x1)) -> a#(b(x1)) c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> b#(x1) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) TDG Processor: DPs: a#(c(c(c(x1)))) -> d#(x1) a#(c(c(c(x1)))) -> d#(d(x1)) b#(d(x1)) -> c#(x1) b#(d(x1)) -> c#(c(x1)) c#(b(x1)) -> a#(b(x1)) c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> b#(x1) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) graph: c#(b(x1)) -> c#(a(b(x1))) -> c#(b(x1)) -> c#(a(b(x1))) c#(b(x1)) -> c#(a(b(x1))) -> c#(b(x1)) -> a#(b(x1)) c#(b(x1)) -> a#(b(x1)) -> a#(c(c(c(x1)))) -> d#(d(x1)) c#(b(x1)) -> a#(b(x1)) -> a#(c(c(c(x1)))) -> d#(x1) b#(d(x1)) -> c#(c(x1)) -> c#(b(x1)) -> c#(a(b(x1))) b#(d(x1)) -> c#(c(x1)) -> c#(b(x1)) -> a#(b(x1)) b#(d(x1)) -> c#(x1) -> c#(b(x1)) -> c#(a(b(x1))) b#(d(x1)) -> c#(x1) -> c#(b(x1)) -> a#(b(x1)) d#(x1) -> c#(b(x1)) -> c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> c#(b(x1)) -> c#(b(x1)) -> a#(b(x1)) d#(x1) -> b#(x1) -> b#(d(x1)) -> c#(c(x1)) d#(x1) -> b#(x1) -> b#(d(x1)) -> c#(x1) a#(c(c(c(x1)))) -> d#(d(x1)) -> d#(x1) -> c#(b(x1)) a#(c(c(c(x1)))) -> d#(d(x1)) -> d#(x1) -> b#(x1) a#(c(c(c(x1)))) -> d#(x1) -> d#(x1) -> c#(b(x1)) a#(c(c(c(x1)))) -> d#(x1) -> d#(x1) -> b#(x1) EDG Processor: DPs: a#(c(c(c(x1)))) -> d#(x1) a#(c(c(c(x1)))) -> d#(d(x1)) b#(d(x1)) -> c#(x1) b#(d(x1)) -> c#(c(x1)) c#(b(x1)) -> a#(b(x1)) c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> b#(x1) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) graph: c#(b(x1)) -> a#(b(x1)) -> a#(c(c(c(x1)))) -> d#(x1) c#(b(x1)) -> a#(b(x1)) -> a#(c(c(c(x1)))) -> d#(d(x1)) b#(d(x1)) -> c#(x1) -> c#(b(x1)) -> a#(b(x1)) b#(d(x1)) -> c#(x1) -> c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> c#(b(x1)) -> c#(b(x1)) -> a#(b(x1)) d#(x1) -> c#(b(x1)) -> c#(b(x1)) -> c#(a(b(x1))) d#(x1) -> b#(x1) -> b#(d(x1)) -> c#(x1) d#(x1) -> b#(x1) -> b#(d(x1)) -> c#(c(x1)) a#(c(c(c(x1)))) -> d#(d(x1)) -> d#(x1) -> b#(x1) a#(c(c(c(x1)))) -> d#(d(x1)) -> d#(x1) -> c#(b(x1)) a#(c(c(c(x1)))) -> d#(x1) -> d#(x1) -> b#(x1) a#(c(c(c(x1)))) -> d#(x1) -> d#(x1) -> c#(b(x1)) SCC Processor: #sccs: 1 #rules: 6 #arcs: 12/64 DPs: c#(b(x1)) -> a#(b(x1)) a#(c(c(c(x1)))) -> d#(d(x1)) d#(x1) -> c#(b(x1)) d#(x1) -> b#(x1) b#(d(x1)) -> c#(x1) a#(c(c(c(x1)))) -> d#(x1) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) Arctic Interpretation Processor: dimension: 1 usable rules: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) interpretation: [a#](x0) = x0 + 0, [c](x0) = 8x0 + 5, [b](x0) = 4x0 + 0, [d#](x0) = 8x0 + 0, [a](x0) = x0 + 0, [c#](x0) = x0 + 0, [b#](x0) = 6x0, [d](x0) = 12x0 + 9 orientation: c#(b(x1)) = 4x1 + 0 >= 4x1 + 0 = a#(b(x1)) a#(c(c(c(x1)))) = 24x1 + 21 >= 20x1 + 17 = d#(d(x1)) d#(x1) = 8x1 + 0 >= 4x1 + 0 = c#(b(x1)) d#(x1) = 8x1 + 0 >= 6x1 = b#(x1) b#(d(x1)) = 18x1 + 15 >= x1 + 0 = c#(x1) a#(c(c(c(x1)))) = 24x1 + 21 >= 8x1 + 0 = d#(x1) a(c(c(c(x1)))) = 24x1 + 21 >= 24x1 + 21 = d(d(x1)) b(d(x1)) = 16x1 + 13 >= 16x1 + 13 = c(c(x1)) c(b(x1)) = 12x1 + 8 >= 12x1 + 8 = c(a(b(x1))) d(x1) = 12x1 + 9 >= 12x1 + 8 = c(b(x1)) problem: DPs: c#(b(x1)) -> a#(b(x1)) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) Restore Modifier: DPs: c#(b(x1)) -> a#(b(x1)) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) EDG Processor: DPs: c#(b(x1)) -> a#(b(x1)) d#(x1) -> c#(b(x1)) TRS: a(c(c(c(x1)))) -> d(d(x1)) b(d(x1)) -> c(c(x1)) c(b(x1)) -> c(a(b(x1))) d(x1) -> c(b(x1)) graph: d#(x1) -> c#(b(x1)) -> c#(b(x1)) -> a#(b(x1)) SCC Processor: #sccs: 0 #rules: 0 #arcs: 1/4