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