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