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