YES Problem: a(x1) -> x1 a(a(b(x1))) -> b(b(a(a(x1)))) c(b(x1)) -> c(a(x1)) Proof: String Reversal Processor: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) DP Processor: DPs: b#(a(a(x1))) -> b#(x1) b#(a(a(x1))) -> b#(b(x1)) b#(a(a(x1))) -> a#(b(b(x1))) b#(a(a(x1))) -> a#(a(b(b(x1)))) b#(c(x1)) -> a#(c(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) TDG Processor: DPs: b#(a(a(x1))) -> b#(x1) b#(a(a(x1))) -> b#(b(x1)) b#(a(a(x1))) -> a#(b(b(x1))) b#(a(a(x1))) -> a#(a(b(b(x1)))) b#(c(x1)) -> a#(c(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) graph: b#(a(a(x1))) -> b#(b(x1)) -> b#(c(x1)) -> a#(c(x1)) b#(a(a(x1))) -> b#(b(x1)) -> b#(a(a(x1))) -> a#(a(b(b(x1)))) b#(a(a(x1))) -> b#(b(x1)) -> b#(a(a(x1))) -> a#(b(b(x1))) b#(a(a(x1))) -> b#(b(x1)) -> b#(a(a(x1))) -> b#(b(x1)) b#(a(a(x1))) -> b#(b(x1)) -> b#(a(a(x1))) -> b#(x1) b#(a(a(x1))) -> b#(x1) -> b#(c(x1)) -> a#(c(x1)) b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> a#(a(b(b(x1)))) b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> a#(b(b(x1))) b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> b#(b(x1)) b#(a(a(x1))) -> b#(x1) -> b#(a(a(x1))) -> b#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 10/25 DPs: b#(a(a(x1))) -> b#(b(x1)) b#(a(a(x1))) -> b#(x1) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) interpretation: [b#](x0) = [-& 0 ]x0 + [0], [-& 3 ] [1 ] [c](x0) = [-& 0 ]x0 + [-&], [0 -&] [b](x0) = [1 0 ]x0, [0 3] [-&] [a](x0) = [1 0]x0 + [1 ] orientation: b#(a(a(x1))) = [1 4]x1 + [1] >= [1 0]x1 + [0] = b#(b(x1)) b#(a(a(x1))) = [1 4]x1 + [1] >= [-& 0 ]x1 + [0] = b#(x1) [0 3] [-&] a(x1) = [1 0]x1 + [1 ] >= x1 = x1 [4 3] [4] [4 3] [4] b(a(a(x1))) = [5 4]x1 + [5] >= [5 4]x1 + [1] = a(a(b(b(x1)))) [-& 3 ] [1] [-& 3 ] [1] b(c(x1)) = [-& 4 ]x1 + [2] >= [-& 4 ]x1 + [2] = a(c(x1)) problem: DPs: b#(a(a(x1))) -> b#(b(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) Restore Modifier: DPs: b#(a(a(x1))) -> b#(b(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) EDG Processor: DPs: b#(a(a(x1))) -> b#(b(x1)) TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) graph: b#(a(a(x1))) -> b#(b(x1)) -> b#(a(a(x1))) -> b#(b(x1)) Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) interpretation: [b#](x0) = [-& 2 ]x0 + [3], [-& 0 ] [0] [c](x0) = [-& 2 ]x0 + [2], [-& 0 ] [0] [b](x0) = [0 0 ]x0 + [0], [0 0] [0] [a](x0) = [2 0]x0 + [2] orientation: b#(a(a(x1))) = [4 4]x1 + [4] >= [2 2]x1 + [3] = b#(b(x1)) [0 0] [0] a(x1) = [2 0]x1 + [2] >= x1 = x1 [2 2] [2] [2 2] [2] b(a(a(x1))) = [2 2]x1 + [2] >= [2 2]x1 + [2] = a(a(b(b(x1)))) [-& 2 ] [2] [-& 2 ] [2] b(c(x1)) = [-& 2 ]x1 + [2] >= [-& 2 ]x1 + [2] = a(c(x1)) problem: DPs: TRS: a(x1) -> x1 b(a(a(x1))) -> a(a(b(b(x1)))) b(c(x1)) -> a(c(x1)) Qed