YES Problem: a(a(x1)) -> b(b(b(x1))) b(x1) -> c(c(d(x1))) c(x1) -> d(d(d(x1))) b(c(x1)) -> c(b(x1)) b(c(d(x1))) -> a(x1) Proof: DP Processor: DPs: a#(a(x1)) -> b#(x1) a#(a(x1)) -> b#(b(x1)) a#(a(x1)) -> b#(b(b(x1))) b#(x1) -> c#(d(x1)) b#(x1) -> c#(c(d(x1))) b#(c(x1)) -> b#(x1) b#(c(x1)) -> c#(b(x1)) b#(c(d(x1))) -> a#(x1) TRS: a(a(x1)) -> b(b(b(x1))) b(x1) -> c(c(d(x1))) c(x1) -> d(d(d(x1))) b(c(x1)) -> c(b(x1)) b(c(d(x1))) -> a(x1) TDG Processor: DPs: a#(a(x1)) -> b#(x1) a#(a(x1)) -> b#(b(x1)) a#(a(x1)) -> b#(b(b(x1))) b#(x1) -> c#(d(x1)) b#(x1) -> c#(c(d(x1))) b#(c(x1)) -> b#(x1) b#(c(x1)) -> c#(b(x1)) b#(c(d(x1))) -> a#(x1) TRS: a(a(x1)) -> b(b(b(x1))) b(x1) -> c(c(d(x1))) c(x1) -> d(d(d(x1))) b(c(x1)) -> c(b(x1)) b(c(d(x1))) -> a(x1) graph: b#(c(d(x1))) -> a#(x1) -> a#(a(x1)) -> b#(b(b(x1))) b#(c(d(x1))) -> a#(x1) -> a#(a(x1)) -> b#(b(x1)) b#(c(d(x1))) -> a#(x1) -> a#(a(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) -> b#(c(d(x1))) -> a#(x1) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> c#(b(x1)) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) -> b#(x1) -> c#(c(d(x1))) b#(c(x1)) -> b#(x1) -> b#(x1) -> c#(d(x1)) a#(a(x1)) -> b#(b(b(x1))) -> b#(c(d(x1))) -> a#(x1) a#(a(x1)) -> b#(b(b(x1))) -> b#(c(x1)) -> c#(b(x1)) a#(a(x1)) -> b#(b(b(x1))) -> b#(c(x1)) -> b#(x1) a#(a(x1)) -> b#(b(b(x1))) -> b#(x1) -> c#(c(d(x1))) a#(a(x1)) -> b#(b(b(x1))) -> b#(x1) -> c#(d(x1)) a#(a(x1)) -> b#(b(x1)) -> b#(c(d(x1))) -> a#(x1) a#(a(x1)) -> b#(b(x1)) -> b#(c(x1)) -> c#(b(x1)) a#(a(x1)) -> b#(b(x1)) -> b#(c(x1)) -> b#(x1) a#(a(x1)) -> b#(b(x1)) -> b#(x1) -> c#(c(d(x1))) a#(a(x1)) -> b#(b(x1)) -> b#(x1) -> c#(d(x1)) a#(a(x1)) -> b#(x1) -> b#(c(d(x1))) -> a#(x1) a#(a(x1)) -> b#(x1) -> b#(c(x1)) -> c#(b(x1)) a#(a(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) a#(a(x1)) -> b#(x1) -> b#(x1) -> c#(c(d(x1))) a#(a(x1)) -> b#(x1) -> b#(x1) -> c#(d(x1)) SCC Processor: #sccs: 1 #rules: 5 #arcs: 23/64 DPs: b#(c(d(x1))) -> a#(x1) a#(a(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) a#(a(x1)) -> b#(b(x1)) a#(a(x1)) -> b#(b(b(x1))) TRS: a(a(x1)) -> b(b(b(x1))) b(x1) -> c(c(d(x1))) c(x1) -> d(d(d(x1))) b(c(x1)) -> c(b(x1)) b(c(d(x1))) -> a(x1) Matrix Interpretation Processor: dim=1 interpretation: [b#](x0) = 2x0 + 1, [a#](x0) = 2x0 + 8, [c](x0) = x0 + 3, [d](x0) = x0 + 1, [b](x0) = x0 + 7, [a](x0) = x0 + 11 orientation: b#(c(d(x1))) = 2x1 + 9 >= 2x1 + 8 = a#(x1) a#(a(x1)) = 2x1 + 30 >= 2x1 + 1 = b#(x1) b#(c(x1)) = 2x1 + 7 >= 2x1 + 1 = b#(x1) a#(a(x1)) = 2x1 + 30 >= 2x1 + 15 = b#(b(x1)) a#(a(x1)) = 2x1 + 30 >= 2x1 + 29 = b#(b(b(x1))) a(a(x1)) = x1 + 22 >= x1 + 21 = b(b(b(x1))) b(x1) = x1 + 7 >= x1 + 7 = c(c(d(x1))) c(x1) = x1 + 3 >= x1 + 3 = d(d(d(x1))) b(c(x1)) = x1 + 10 >= x1 + 10 = c(b(x1)) b(c(d(x1))) = x1 + 11 >= x1 + 11 = a(x1) problem: DPs: TRS: a(a(x1)) -> b(b(b(x1))) b(x1) -> c(c(d(x1))) c(x1) -> d(d(d(x1))) b(c(x1)) -> c(b(x1)) b(c(d(x1))) -> a(x1) Qed