YES Problem: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) Proof: DP Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> a#(b(c(c(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) TDG Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> a#(b(c(c(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) graph: c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> a#(b(c(c(x1)))) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> a#(b(c(c(x1)))) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> b#(c(c(x1))) -> b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(b(c(c(x1)))) -> a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) -> a#(a(x1)) -> b#(x1) a#(a(x1)) -> b#(x1) -> b#(c(x1)) -> a#(x1) CDG Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> a#(b(c(c(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) graph: c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> c#(c(x1)) -> c#(b(x1)) -> a#(b(c(c(x1)))) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> b#(c(c(x1))) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> a#(b(c(c(x1)))) c#(b(x1)) -> b#(c(c(x1))) -> b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(b(c(c(x1)))) -> a#(a(x1)) -> b#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 10/36 DPs: c#(b(x1)) -> c#(c(x1)) c#(b(x1)) -> c#(x1) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) Arctic Interpretation Processor: dimension: 2 interpretation: [c#](x0) = [0 0]x0, [0 0] [0 ] [c](x0) = [0 0]x0 + [-&], [0 0] [0] [b](x0) = [1 1]x0 + [1], [0 0] [0] [a](x0) = [1 0]x0 + [1] orientation: c#(b(x1)) = [1 1]x1 + [1] >= [0 0]x1 + [0] = c#(c(x1)) c#(b(x1)) = [1 1]x1 + [1] >= [0 0]x1 = c#(x1) [1 0] [1] [0 0] [0] a(a(x1)) = [1 1]x1 + [1] >= [1 1]x1 + [1] = b(x1) [0 0] [0] [0 0] [0] b(c(x1)) = [1 1]x1 + [1] >= [1 0]x1 + [1] = a(x1) [1 1] [1] [1 1] [1] c(b(x1)) = [1 1]x1 + [1] >= [1 1]x1 + [1] = a(b(c(c(x1)))) problem: DPs: TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> a(b(c(c(x1)))) Qed