YES Problem: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Proof: DP Processor: DPs: a#(a(x1)) -> c#(x1) a#(a(x1)) -> b#(c(x1)) a#(a(x1)) -> b#(b(c(x1))) a#(a(x1)) -> a#(b(b(c(x1)))) c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) TDG Processor: DPs: a#(a(x1)) -> c#(x1) a#(a(x1)) -> b#(c(x1)) a#(a(x1)) -> b#(b(c(x1))) a#(a(x1)) -> a#(b(b(c(x1)))) c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) graph: c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> a#(c(x1)) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> a#(b(b(c(x1)))) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> b#(b(c(x1))) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> b#(c(x1)) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> c#(x1) a#(a(x1)) -> c#(x1) -> c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> a#(b(b(c(x1)))) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> b#(b(c(x1))) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> b#(c(x1)) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> c#(x1) SCC Processor: #sccs: 1 #rules: 4 #arcs: 12/36 DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> c#(x1) a#(a(x1)) -> a#(b(b(c(x1)))) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Arctic Interpretation Processor: dimension: 2 interpretation: [c#](x0) = [0 -&]x0 + [0], [a#](x0) = [0 -&]x0 + [0], [0 0] [-&] [b](x0) = [0 1]x0 + [1 ], [-& 0 ] [0] [c](x0) = [0 -&]x0 + [0], [1 0 ] [1] [a](x0) = [0 -&]x0 + [0] orientation: c#(b(x1)) = [0 0]x1 + [0] >= [0 -&]x1 + [0] = c#(x1) c#(b(x1)) = [0 0]x1 + [0] >= [-& 0 ]x1 + [0] = a#(c(x1)) a#(a(x1)) = [1 0]x1 + [1] >= [0 -&]x1 + [0] = c#(x1) a#(a(x1)) = [1 0]x1 + [1] >= [1 0]x1 + [1] = a#(b(b(c(x1)))) [2 1] [2] [2 1] [2] a(a(x1)) = [1 0]x1 + [1] >= [1 0]x1 + [1] = a(b(b(c(x1)))) [1 0] [1] b(a(x1)) = [1 0]x1 + [1] >= x1 = x1 [0 1] [1] [0 1 ] [1] c(b(x1)) = [0 0]x1 + [0] >= [-& 0 ]x1 + [0] = a(c(x1)) problem: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> a#(b(b(c(x1)))) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) EDG Processor: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> a#(b(b(c(x1)))) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) graph: c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) c#(b(x1)) -> c#(x1) -> c#(b(x1)) -> a#(c(x1)) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> a#(b(b(c(x1)))) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> a#(b(b(c(x1)))) CDG Processor: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> a#(b(b(c(x1)))) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) graph: c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> a#(b(b(c(x1)))) a#(a(x1)) -> a#(b(b(c(x1)))) -> a#(a(x1)) -> a#(b(b(c(x1)))) SCC Processor: #sccs: 1 #rules: 1 #arcs: 2/9 DPs: a#(a(x1)) -> a#(b(b(c(x1)))) TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Arctic Interpretation Processor: dimension: 3 interpretation: [a#](x0) = [-& -& 0 ]x0 + [0], [-& 0 -&] [0] [b](x0) = [0 1 0 ]x0 + [1] [0 -& -&] [0], [-& 0 -&] [0] [c](x0) = [0 -& -&]x0 + [0] [0 0 0 ] [1], [1 0 0 ] [1] [a](x0) = [0 -& -&]x0 + [0] [1 0 0 ] [1] orientation: a#(a(x1)) = [1 0 0]x1 + [1] >= [0 -& -&]x1 + [0] = a#(b(b(c(x1)))) [2 1 1] [2] [2 1 1] [2] a(a(x1)) = [1 0 0]x1 + [1] >= [1 0 0]x1 + [1] = a(b(b(c(x1)))) [2 1 1] [2] [2 1 1] [2] [0 -& -&] [0] b(a(x1)) = [1 0 0 ]x1 + [1] >= x1 = x1 [1 0 0 ] [1] [0 1 0 ] [1] [0 1 0 ] [1] c(b(x1)) = [-& 0 -&]x1 + [0] >= [-& 0 -&]x1 + [0] = a(c(x1)) [0 1 0 ] [1] [0 1 0 ] [1] problem: DPs: TRS: a(a(x1)) -> a(b(b(c(x1)))) b(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Qed