YES Problem: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Proof: DP Processor: DPs: a#(a(x1)) -> 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)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) TDG Processor: DPs: a#(a(x1)) -> 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)))) c(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)) -> 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)) -> c#(x1) EDG Processor: DPs: a#(a(x1)) -> 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)))) c(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)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) -> a#(a(x1)) -> a#(b(b(c(x1)))) a#(a(x1)) -> c#(x1) -> c#(b(x1)) -> c#(x1) a#(a(x1)) -> c#(x1) -> c#(b(x1)) -> a#(c(x1)) SCC Processor: #sccs: 1 #rules: 3 #arcs: 6/16 DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) a#(a(x1)) -> c#(x1) TRS: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Arctic Interpretation Processor: dimension: 2 usable rules: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) interpretation: [c#](x0) = [0 3]x0 + [0], [-& 0 ] [0] [c](x0) = [0 -&]x0 + [0], [a#](x0) = [3 2]x0 + [0], [-& 0 ] [0] [a](x0) = [0 2 ]x0 + [3], [2 0] [3] [b](x0) = [0 0]x0 + [0] orientation: c#(b(x1)) = [3 3]x1 + [3] >= [0 3]x1 + [0] = c#(x1) c#(b(x1)) = [3 3]x1 + [3] >= [2 3]x1 + [3] = a#(c(x1)) a#(a(x1)) = [2 4]x1 + [5] >= [0 3]x1 + [0] = c#(x1) [0 2] [3] [0 2] [3] a(a(x1)) = [2 4]x1 + [5] >= [2 4]x1 + [5] = a(b(b(c(x1)))) [0 2 ] [3] c(a(x1)) = [-& 0 ]x1 + [0] >= x1 = x1 [0 0] [0] [0 -&] [0] c(b(x1)) = [2 0]x1 + [3] >= [2 0 ]x1 + [3] = a(c(x1)) problem: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) TRS: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Restore Modifier: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) TRS: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) EDG Processor: DPs: c#(b(x1)) -> c#(x1) c#(b(x1)) -> a#(c(x1)) TRS: a(a(x1)) -> a(b(b(c(x1)))) c(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) SCC Processor: #sccs: 1 #rules: 1 #arcs: 2/4 DPs: c#(b(x1)) -> c#(x1) TRS: a(a(x1)) -> a(b(b(c(x1)))) c(a(x1)) -> x1 c(b(x1)) -> a(c(x1)) Usable Rule Processor: DPs: c#(b(x1)) -> c#(x1) TRS: Arctic Interpretation Processor: dimension: 3 usable rules: interpretation: [c#](x0) = [1 -& -&]x0, [1 1 0] [0] [b](x0) = [1 1 1]x0 + [0] [1 1 1] [0] orientation: c#(b(x1)) = [2 2 1]x1 + [1] >= [1 -& -&]x1 = c#(x1) problem: DPs: TRS: Qed