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