YES Problem: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) Proof: DP Processor: DPs: a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> c#(b(a(a(x1)))) b#(x1) -> c#(x1) c#(c(x1)) -> b#(x1) TRS: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) TDG Processor: DPs: a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> c#(b(a(a(x1)))) b#(x1) -> c#(x1) c#(c(x1)) -> b#(x1) TRS: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) graph: c#(c(x1)) -> b#(x1) -> b#(x1) -> c#(x1) b#(x1) -> c#(x1) -> c#(c(x1)) -> b#(x1) a#(b(x1)) -> c#(b(a(a(x1)))) -> c#(c(x1)) -> b#(x1) a#(b(x1)) -> b#(a(a(x1))) -> b#(x1) -> c#(x1) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> c#(b(a(a(x1)))) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> c#(b(a(a(x1)))) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> a#(x1) CDG Processor: DPs: a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> c#(b(a(a(x1)))) b#(x1) -> c#(x1) c#(c(x1)) -> b#(x1) TRS: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) graph: c#(c(x1)) -> b#(x1) -> b#(x1) -> c#(x1) a#(b(x1)) -> c#(b(a(a(x1)))) -> c#(c(x1)) -> b#(x1) a#(b(x1)) -> b#(a(a(x1))) -> b#(x1) -> c#(x1) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> a#(a(x1)) -> a#(b(x1)) -> c#(b(a(a(x1)))) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> a#(x1) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> b#(a(a(x1))) a#(b(x1)) -> a#(x1) -> a#(b(x1)) -> c#(b(a(a(x1)))) SCC Processor: #sccs: 1 #rules: 2 #arcs: 11/36 DPs: a#(b(x1)) -> a#(a(x1)) a#(b(x1)) -> a#(x1) TRS: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) interpretation: [a#](x0) = [0 1]x0, [-& 0 ] [0] [c](x0) = [2 0 ]x0 + [3], [-& 0 ] [0] [b](x0) = [2 2 ]x0 + [3], [0 0] [1] [a](x0) = [0 0]x0 + [0] orientation: a#(b(x1)) = [3 3]x1 + [4] >= [1 1]x1 + [1] = a#(a(x1)) a#(b(x1)) = [3 3]x1 + [4] >= [0 1]x1 = a#(x1) [0 0] [1] a(x1) = [0 0]x1 + [0] >= x1 = x1 [2 2] [3] [2 2] [3] a(b(x1)) = [2 2]x1 + [3] >= [2 2]x1 + [3] = c(b(a(a(x1)))) [-& 0 ] [0] [-& 0 ] [0] b(x1) = [2 2 ]x1 + [3] >= [2 0 ]x1 + [3] = c(x1) [2 0] [3] [-& 0 ] [0] c(c(x1)) = [2 2]x1 + [3] >= [2 2 ]x1 + [3] = b(x1) problem: DPs: TRS: a(x1) -> x1 a(b(x1)) -> c(b(a(a(x1)))) b(x1) -> c(x1) c(c(x1)) -> b(x1) Qed