YES Problem: a(x1) -> x1 a(b(x1)) -> b(b(a(c(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) Proof: String Reversal Processor: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) DP Processor: DPs: b#(a(x1)) -> b#(x1) b#(a(x1)) -> b#(b(x1)) b#(a(x1)) -> a#(b(b(x1))) b#(a(x1)) -> c#(a(b(b(x1)))) c#(b(c(x1))) -> a#(x1) TRS: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) TDG Processor: DPs: b#(a(x1)) -> b#(x1) b#(a(x1)) -> b#(b(x1)) b#(a(x1)) -> a#(b(b(x1))) b#(a(x1)) -> c#(a(b(b(x1)))) c#(b(c(x1))) -> a#(x1) TRS: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) graph: b#(a(x1)) -> c#(a(b(b(x1)))) -> c#(b(c(x1))) -> a#(x1) b#(a(x1)) -> b#(b(x1)) -> b#(a(x1)) -> c#(a(b(b(x1)))) b#(a(x1)) -> b#(b(x1)) -> b#(a(x1)) -> a#(b(b(x1))) b#(a(x1)) -> b#(b(x1)) -> b#(a(x1)) -> b#(b(x1)) b#(a(x1)) -> b#(b(x1)) -> b#(a(x1)) -> b#(x1) b#(a(x1)) -> b#(x1) -> b#(a(x1)) -> c#(a(b(b(x1)))) b#(a(x1)) -> b#(x1) -> b#(a(x1)) -> a#(b(b(x1))) b#(a(x1)) -> b#(x1) -> b#(a(x1)) -> b#(b(x1)) b#(a(x1)) -> b#(x1) -> b#(a(x1)) -> b#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 9/25 DPs: b#(a(x1)) -> b#(b(x1)) b#(a(x1)) -> b#(x1) TRS: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) Arctic Interpretation Processor: dimension: 3 usable rules: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) interpretation: [b#](x0) = [0 1 0]x0 + [0], [0 0 0 ] [0] [c](x0) = [0 0 0 ]x0 + [0] [0 -& -&] [0], [0 1 -&] [0 ] [b](x0) = [-& 0 -&]x0 + [-&] [-& 0 0 ] [0 ], [0 0 -&] [0] [a](x0) = [0 1 0 ]x0 + [0] [0 0 0 ] [0] orientation: b#(a(x1)) = [1 2 1]x1 + [1] >= [0 1 0]x1 + [0] = b#(b(x1)) b#(a(x1)) = [1 2 1]x1 + [1] >= [0 1 0]x1 + [0] = b#(x1) [0 0 -&] [0] a(x1) = [0 1 0 ]x1 + [0] >= x1 = x1 [0 0 0 ] [0] [1 2 1] [1] [0 1 0 ] [0] b(a(x1)) = [0 1 0]x1 + [0] >= [0 1 0 ]x1 + [0] = c(a(b(b(x1)))) [0 1 0] [0] [0 1 -&] [0] [0 1 -&] [0 ] b(x1) = [-& 0 -&]x1 + [-&] >= x1 = x1 [-& 0 0 ] [0 ] [1 1 1] [1] [0 0 -&] [0] c(b(c(x1))) = [1 1 1]x1 + [1] >= [0 1 0 ]x1 + [0] = a(x1) [1 1 1] [1] [0 0 0 ] [0] problem: DPs: TRS: a(x1) -> x1 b(a(x1)) -> c(a(b(b(x1)))) b(x1) -> x1 c(b(c(x1))) -> a(x1) Qed