YES Problem: a(a(x1)) -> x1 a(b(x1)) -> c(c(x1)) c(b(x1)) -> b(b(a(x1))) Proof: String Reversal Processor: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) DP Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> a#(b(b(x1))) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) TDG Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> a#(b(b(x1))) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) graph: b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(b(x1)) -> b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> a#(b(b(x1))) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) SCC Processor: #sccs: 1 #rules: 2 #arcs: 6/9 DPs: b#(c(x1)) -> b#(b(x1)) b#(c(x1)) -> b#(x1) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) Arctic Interpretation Processor: dimension: 3 usable rules: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) interpretation: [b#](x0) = [0 0 1]x0 + [0], [0 -& -&] [0] [c](x0) = [1 0 0 ]x0 + [1] [1 -& 0 ] [1], [-& -& 0 ] [0] [b](x0) = [0 -& 0 ]x0 + [1] [0 -& -&] [0], [1 0 0 ] [1 ] [a](x0) = [0 0 0 ]x0 + [-&] [0 -& -&] [0 ] orientation: b#(c(x1)) = [2 0 1]x1 + [2] >= [1 -& 0 ]x1 + [1] = b#(b(x1)) b#(c(x1)) = [2 0 1]x1 + [2] >= [0 0 1]x1 + [0] = b#(x1) [2 1 1] [2] a(a(x1)) = [1 0 0]x1 + [1] >= x1 = x1 [1 0 0] [1] [0 -& -&] [0] [0 -& -&] [0] b(a(x1)) = [1 0 0 ]x1 + [1] >= [1 0 0 ]x1 + [1] = c(c(x1)) [1 0 0 ] [1] [1 -& 0 ] [1] [1 -& 0 ] [1] [1 -& 0 ] [1] b(c(x1)) = [1 -& 0 ]x1 + [1] >= [0 -& 0 ]x1 + [1] = a(b(b(x1))) [0 -& -&] [0] [0 -& -&] [0] problem: DPs: b#(c(x1)) -> b#(x1) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) Restore Modifier: DPs: b#(c(x1)) -> b#(x1) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) EDG Processor: DPs: b#(c(x1)) -> b#(x1) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) graph: b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) CDG Processor: DPs: b#(c(x1)) -> b#(x1) TRS: a(a(x1)) -> x1 b(a(x1)) -> c(c(x1)) b(c(x1)) -> a(b(b(x1))) graph: Qed