YES Problem: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) Proof: DP Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(x1) c#(b(x1)) -> c#(a(x1)) c#(b(x1)) -> c#(c(a(x1))) c#(b(x1)) -> b#(c(c(a(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) TDG Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(x1) c#(b(x1)) -> c#(a(x1)) c#(b(x1)) -> c#(c(a(x1))) c#(b(x1)) -> b#(c(c(a(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) graph: c#(b(x1)) -> c#(c(a(x1))) -> c#(b(x1)) -> b#(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)) -> b#(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) c#(b(x1)) -> b#(c(c(a(x1)))) -> b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(x1) -> a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) -> a#(a(x1)) -> b#(x1) a#(a(x1)) -> b#(x1) -> b#(c(x1)) -> a#(x1) CDG Processor: DPs: a#(a(x1)) -> b#(x1) b#(c(x1)) -> a#(x1) c#(b(x1)) -> a#(x1) c#(b(x1)) -> c#(a(x1)) c#(b(x1)) -> c#(c(a(x1))) c#(b(x1)) -> b#(c(c(a(x1)))) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) graph: c#(b(x1)) -> c#(c(a(x1))) -> c#(b(x1)) -> 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)) -> c#(c(a(x1))) c#(b(x1)) -> c#(c(a(x1))) -> c#(b(x1)) -> b#(c(c(a(x1)))) c#(b(x1)) -> c#(a(x1)) -> c#(b(x1)) -> a#(x1) c#(b(x1)) -> c#(a(x1)) -> c#(b(x1)) -> 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)) -> b#(c(c(a(x1)))) c#(b(x1)) -> b#(c(c(a(x1)))) -> b#(c(x1)) -> a#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 9/36 DPs: c#(b(x1)) -> c#(c(a(x1))) c#(b(x1)) -> c#(a(x1)) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) Arctic Interpretation Processor: dimension: 3 interpretation: [c#](x0) = [-& 0 0 ]x0 + [0], [-& 0 0 ] [0] [c](x0) = [-& -& 0 ]x0 + [0] [0 -& 0 ] [0], [0 0 0] [0] [b](x0) = [1 0 0]x0 + [0] [0 1 0] [1], [-& 0 -&] [0] [a](x0) = [0 1 0 ]x0 + [1] [-& 0 -&] [0] orientation: c#(b(x1)) = [1 1 0]x1 + [1] >= [-& 0 -&]x1 + [0] = c#(c(a(x1))) c#(b(x1)) = [1 1 0]x1 + [1] >= [0 1 0]x1 + [1] = c#(a(x1)) [0 1 0] [1] [0 0 0] [0] a(a(x1)) = [1 2 1]x1 + [2] >= [1 0 0]x1 + [0] = b(x1) [0 1 0] [1] [0 1 0] [1] [0 0 0] [0] [-& 0 -&] [0] b(c(x1)) = [0 1 1]x1 + [1] >= [0 1 0 ]x1 + [1] = a(x1) [0 0 1] [1] [-& 0 -&] [0] [1 1 0] [1] [0 1 0] [1] c(b(x1)) = [0 1 0]x1 + [1] >= [0 1 0]x1 + [1] = b(c(c(a(x1)))) [0 1 0] [1] [0 1 0] [1] problem: DPs: c#(b(x1)) -> c#(a(x1)) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) EDG Processor: DPs: c#(b(x1)) -> c#(a(x1)) TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) graph: c#(b(x1)) -> c#(a(x1)) -> c#(b(x1)) -> c#(a(x1)) Arctic Interpretation Processor: dimension: 3 interpretation: [c#](x0) = [-& 0 0 ]x0 + [0], [-& 0 0 ] [0] [c](x0) = [0 1 1 ]x0 + [1] [0 -& -&] [0], [0 -& 1 ] [-&] [b](x0) = [1 0 0 ]x0 + [1 ] [-& -& -&] [0 ], [1 0 0 ] [1 ] [a](x0) = [0 -& -&]x0 + [-&] [-& -& -&] [0 ] orientation: c#(b(x1)) = [1 0 0]x1 + [1] >= [0 -& -&]x1 + [0] = c#(a(x1)) [2 1 1 ] [2] [0 -& 1 ] [-&] a(a(x1)) = [1 0 0 ]x1 + [1] >= [1 0 0 ]x1 + [1 ] = b(x1) [-& -& -&] [0] [-& -& -&] [0 ] [1 0 0 ] [1] [1 0 0 ] [1 ] b(c(x1)) = [0 1 1 ]x1 + [1] >= [0 -& -&]x1 + [-&] = a(x1) [-& -& -&] [0] [-& -& -&] [0 ] [1 0 0 ] [1] [1 0 0 ] [1] c(b(x1)) = [2 1 1 ]x1 + [2] >= [2 1 1 ]x1 + [2] = b(c(c(a(x1)))) [0 -& 1 ] [0] [-& -& -&] [0] problem: DPs: TRS: a(a(x1)) -> b(x1) b(c(x1)) -> a(x1) c(b(x1)) -> b(c(c(a(x1)))) Qed