YES Problem: a(x1) -> x1 a(a(b(x1))) -> c(c(b(a(x1)))) b(c(x1)) -> a(b(x1)) Proof: String Reversal Processor: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) DP Processor: DPs: b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> c#(c(x1)) b#(a(a(x1))) -> b#(c(c(x1))) b#(a(a(x1))) -> a#(b(c(c(x1)))) c#(b(x1)) -> a#(x1) c#(b(x1)) -> b#(a(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) TDG Processor: DPs: b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> c#(c(x1)) b#(a(a(x1))) -> b#(c(c(x1))) b#(a(a(x1))) -> a#(b(c(c(x1)))) c#(b(x1)) -> a#(x1) c#(b(x1)) -> b#(a(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) graph: c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> a#(b(c(c(x1)))) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> b#(c(c(x1))) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> c#(c(x1)) c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> c#(c(x1)) -> c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> c#(c(x1)) -> c#(b(x1)) -> a#(x1) b#(a(a(x1))) -> c#(x1) -> c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> c#(x1) -> c#(b(x1)) -> a#(x1) b#(a(a(x1))) -> b#(c(c(x1))) -> b#(a(a(x1))) -> a#(b(c(c(x1)))) b#(a(a(x1))) -> b#(c(c(x1))) -> b#(a(a(x1))) -> b#(c(c(x1))) b#(a(a(x1))) -> b#(c(c(x1))) -> b#(a(a(x1))) -> c#(c(x1)) b#(a(a(x1))) -> b#(c(c(x1))) -> b#(a(a(x1))) -> c#(x1) SCC Processor: #sccs: 1 #rules: 4 #arcs: 12/36 DPs: c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> c#(x1) b#(a(a(x1))) -> c#(c(x1)) b#(a(a(x1))) -> b#(c(c(x1))) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) Arctic Interpretation Processor: dimension: 1 interpretation: [c#](x0) = x0, [b#](x0) = 1x0 + 0, [c](x0) = x0, [b](x0) = 1x0 + 0, [a](x0) = x0 + -1 orientation: c#(b(x1)) = 1x1 + 0 >= 1x1 + 0 = b#(a(x1)) b#(a(a(x1))) = 1x1 + 0 >= x1 = c#(x1) b#(a(a(x1))) = 1x1 + 0 >= x1 = c#(c(x1)) b#(a(a(x1))) = 1x1 + 0 >= 1x1 + 0 = b#(c(c(x1))) a(x1) = x1 + -1 >= x1 = x1 b(a(a(x1))) = 1x1 + 0 >= 1x1 + 0 = a(b(c(c(x1)))) c(b(x1)) = 1x1 + 0 >= 1x1 + 0 = b(a(x1)) problem: DPs: c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> b#(c(c(x1))) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) EDG Processor: DPs: c#(b(x1)) -> b#(a(x1)) b#(a(a(x1))) -> b#(c(c(x1))) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) graph: c#(b(x1)) -> b#(a(x1)) -> b#(a(a(x1))) -> b#(c(c(x1))) b#(a(a(x1))) -> b#(c(c(x1))) -> b#(a(a(x1))) -> b#(c(c(x1))) SCC Processor: #sccs: 1 #rules: 1 #arcs: 2/4 DPs: b#(a(a(x1))) -> b#(c(c(x1))) TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) Arctic Interpretation Processor: dimension: 4 interpretation: [b#](x0) = [0 1 0 0]x0 + [0], [-& 0 0 0 ] [0 ] [-& -& -& -&] [-&] [c](x0) = [-& 0 0 0 ]x0 + [0 ] [-& 0 0 0 ] [0 ], [0 0 0 0 ] [1 ] [-& -& -& -&] [-&] [b](x0) = [1 0 1 1 ]x0 + [1 ] [-& 1 -& -&] [-&], [0 0 -& 0 ] [0 ] [-& 0 -& 0 ] [-&] [a](x0) = [0 0 0 0 ]x0 + [0 ] [-& 0 0 0 ] [0 ] orientation: b#(a(a(x1))) = [0 1 1 1]x1 + [1] >= [-& 0 0 0 ]x1 + [0] = b#(c(c(x1))) [0 0 -& 0 ] [0 ] [-& 0 -& 0 ] [-&] a(x1) = [0 0 0 0 ]x1 + [0 ] >= x1 = x1 [-& 0 0 0 ] [0 ] [0 0 0 0 ] [1 ] [-& 0 0 0 ] [1 ] [-& -& -& -&] [-&] [-& -& -& -&] [-&] b(a(a(x1))) = [1 1 1 1 ]x1 + [1 ] >= [-& 1 1 1 ]x1 + [1 ] = a(b(c(c(x1)))) [-& 1 1 1 ] [1 ] [-& 1 1 1 ] [1 ] [1 1 1 1 ] [1 ] [0 0 0 0 ] [1 ] [-& -& -& -&] [-&] [-& -& -& -&] [-&] c(b(x1)) = [1 1 1 1 ]x1 + [1 ] >= [1 1 1 1 ]x1 + [1 ] = b(a(x1)) [1 1 1 1 ] [1 ] [-& 1 -& 1 ] [-&] problem: DPs: TRS: a(x1) -> x1 b(a(a(x1))) -> a(b(c(c(x1)))) c(b(x1)) -> b(a(x1)) Qed