YES Problem: a(x1) -> x1 a(b(c(x1))) -> b(c(c(a(x1)))) c(x1) -> b(a(x1)) Proof: String Reversal Processor: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) DP Processor: DPs: c#(b(a(x1))) -> c#(b(x1)) c#(b(a(x1))) -> c#(c(b(x1))) c#(b(a(x1))) -> a#(c(c(b(x1)))) c#(x1) -> a#(b(x1)) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) TDG Processor: DPs: c#(b(a(x1))) -> c#(b(x1)) c#(b(a(x1))) -> c#(c(b(x1))) c#(b(a(x1))) -> a#(c(c(b(x1)))) c#(x1) -> a#(b(x1)) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) graph: c#(b(a(x1))) -> c#(b(x1)) -> c#(x1) -> a#(b(x1)) c#(b(a(x1))) -> c#(b(x1)) -> c#(b(a(x1))) -> a#(c(c(b(x1)))) c#(b(a(x1))) -> c#(b(x1)) -> c#(b(a(x1))) -> c#(c(b(x1))) c#(b(a(x1))) -> c#(b(x1)) -> c#(b(a(x1))) -> c#(b(x1)) c#(b(a(x1))) -> c#(c(b(x1))) -> c#(x1) -> a#(b(x1)) c#(b(a(x1))) -> c#(c(b(x1))) -> c#(b(a(x1))) -> a#(c(c(b(x1)))) c#(b(a(x1))) -> c#(c(b(x1))) -> c#(b(a(x1))) -> c#(c(b(x1))) c#(b(a(x1))) -> c#(c(b(x1))) -> c#(b(a(x1))) -> c#(b(x1)) SCC Processor: #sccs: 1 #rules: 2 #arcs: 8/16 DPs: c#(b(a(x1))) -> c#(b(x1)) c#(b(a(x1))) -> c#(c(b(x1))) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) interpretation: [c#](x0) = [0 0]x0 + [0], [0 0] [0] [c](x0) = [1 0]x0 + [1], [0 0] [0] [a](x0) = [0 1]x0 + [1], [-& 0 ] [0] [b](x0) = [-& -&]x0 + [0] orientation: c#(b(a(x1))) = [0 1]x1 + [1] >= [-& 0 ]x1 + [0] = c#(b(x1)) c#(b(a(x1))) = [0 1]x1 + [1] >= [-& 1 ]x1 + [1] = c#(c(b(x1))) [0 0] [0] a(x1) = [0 1]x1 + [1] >= x1 = x1 [0 1] [1] [-& 1 ] [1] c(b(a(x1))) = [1 2]x1 + [2] >= [-& 2 ]x1 + [2] = a(c(c(b(x1)))) [0 0] [0] [-& 0 ] [0] c(x1) = [1 0]x1 + [1] >= [-& 0 ]x1 + [1] = a(b(x1)) problem: DPs: c#(b(a(x1))) -> c#(c(b(x1))) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) Restore Modifier: DPs: c#(b(a(x1))) -> c#(c(b(x1))) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) EDG Processor: DPs: c#(b(a(x1))) -> c#(c(b(x1))) TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) graph: c#(b(a(x1))) -> c#(c(b(x1))) -> c#(b(a(x1))) -> c#(c(b(x1))) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) interpretation: [c#](x0) = [-& 0 ]x0 + [0], [0 1] [1] [c](x0) = [0 0]x0 + [0], [1 0 ] [1 ] [a](x0) = [-& 0 ]x0 + [-&], [-& -&] [0] [b](x0) = [0 -&]x0 + [0] orientation: c#(b(a(x1))) = [1 0]x1 + [1] >= [0 -&]x1 + [0] = c#(c(b(x1))) [1 0 ] [1 ] a(x1) = [-& 0 ]x1 + [-&] >= x1 = x1 [2 1] [2] [2 -&] [2] c(b(a(x1))) = [1 0]x1 + [1] >= [1 -&]x1 + [1] = a(c(c(b(x1)))) [0 1] [1] [0 -&] [1] c(x1) = [0 0]x1 + [0] >= [0 -&]x1 + [0] = a(b(x1)) problem: DPs: TRS: a(x1) -> x1 c(b(a(x1))) -> a(c(c(b(x1)))) c(x1) -> a(b(x1)) Qed