YES Problem: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) Proof: DP Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> a#(a(b(b(x1)))) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) TDG Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> a#(a(b(b(x1)))) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) graph: b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> a#(a(b(b(x1)))) b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> a#(a(b(b(x1)))) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 8/16 DPs: b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(x1) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) Arctic Interpretation Processor: dimension: 1 usable rules: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) interpretation: [b#](x0) = 6x0 + 8, [a](x0) = 3x0 + 4, [b](x0) = -3x0 + 0, [c](x0) = 3x0 + 10 orientation: b#(c(x1)) = 9x1 + 16 >= 3x1 + 8 = b#(b(x1)) b#(c(x1)) = 9x1 + 16 >= 6x1 + 8 = b#(x1) a(b(x1)) = x1 + 4 >= x1 = x1 a(c(x1)) = 6x1 + 13 >= 6x1 + 13 = c(c(x1)) b(c(x1)) = x1 + 7 >= x1 + 7 = a(a(b(b(x1)))) problem: DPs: TRS: a(b(x1)) -> x1 a(c(x1)) -> c(c(x1)) b(c(x1)) -> a(a(b(b(x1)))) Qed