YES Problem: a(x1) -> x1 a(x1) -> b(b(c(x1))) a(c(b(x1))) -> c(a(a(x1))) c(x1) -> x1 Proof: String Reversal Processor: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 DP Processor: DPs: a#(x1) -> b#(x1) a#(x1) -> b#(b(x1)) a#(x1) -> c#(b(b(x1))) b#(c(a(x1))) -> c#(x1) b#(c(a(x1))) -> a#(c(x1)) b#(c(a(x1))) -> a#(a(c(x1))) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 TDG Processor: DPs: a#(x1) -> b#(x1) a#(x1) -> b#(b(x1)) a#(x1) -> c#(b(b(x1))) b#(c(a(x1))) -> c#(x1) b#(c(a(x1))) -> a#(c(x1)) b#(c(a(x1))) -> a#(a(c(x1))) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 graph: b#(c(a(x1))) -> a#(c(x1)) -> a#(x1) -> c#(b(b(x1))) b#(c(a(x1))) -> a#(c(x1)) -> a#(x1) -> b#(b(x1)) b#(c(a(x1))) -> a#(c(x1)) -> a#(x1) -> b#(x1) b#(c(a(x1))) -> a#(a(c(x1))) -> a#(x1) -> c#(b(b(x1))) b#(c(a(x1))) -> a#(a(c(x1))) -> a#(x1) -> b#(b(x1)) b#(c(a(x1))) -> a#(a(c(x1))) -> a#(x1) -> b#(x1) a#(x1) -> b#(b(x1)) -> b#(c(a(x1))) -> a#(a(c(x1))) a#(x1) -> b#(b(x1)) -> b#(c(a(x1))) -> a#(c(x1)) a#(x1) -> b#(b(x1)) -> b#(c(a(x1))) -> c#(x1) a#(x1) -> b#(x1) -> b#(c(a(x1))) -> a#(a(c(x1))) a#(x1) -> b#(x1) -> b#(c(a(x1))) -> a#(c(x1)) a#(x1) -> b#(x1) -> b#(c(a(x1))) -> c#(x1) SCC Processor: #sccs: 1 #rules: 4 #arcs: 12/36 DPs: b#(c(a(x1))) -> a#(c(x1)) a#(x1) -> b#(x1) b#(c(a(x1))) -> a#(a(c(x1))) a#(x1) -> b#(b(x1)) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 Arctic Interpretation Processor: dimension: 2 usable rules: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 interpretation: [b#](x0) = [-& 0 ]x0 + [0], [0 0] [-&] [c](x0) = [0 0]x0 + [-2], [a#](x0) = [-& 1 ]x0 + [1], [1 1 ] [1] [a](x0) = [-& 0 ]x0 + [0], [-& 1 ] [0 ] [b](x0) = [-& -1]x0 + [-&] orientation: b#(c(a(x1))) = [1 1]x1 + [1] >= [1 1]x1 + [1] = a#(c(x1)) a#(x1) = [-& 1 ]x1 + [1] >= [-& 0 ]x1 + [0] = b#(x1) b#(c(a(x1))) = [1 1]x1 + [1] >= [1 1]x1 + [1] = a#(a(c(x1))) a#(x1) = [-& 1 ]x1 + [1] >= [-& -1]x1 + [0] = b#(b(x1)) [1 1 ] [1] a(x1) = [-& 0 ]x1 + [0] >= x1 = x1 [1 1 ] [1] [-& 0 ] [0] a(x1) = [-& 0 ]x1 + [0] >= [-& 0 ]x1 + [0] = c(b(b(x1))) [2 2] [2] [2 2] [2] b(c(a(x1))) = [0 0]x1 + [0] >= [0 0]x1 + [0] = a(a(c(x1))) [0 0] [-&] c(x1) = [0 0]x1 + [-2] >= x1 = x1 problem: DPs: b#(c(a(x1))) -> a#(c(x1)) b#(c(a(x1))) -> a#(a(c(x1))) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 Restore Modifier: DPs: b#(c(a(x1))) -> a#(c(x1)) b#(c(a(x1))) -> a#(a(c(x1))) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 EDG Processor: DPs: b#(c(a(x1))) -> a#(c(x1)) b#(c(a(x1))) -> a#(a(c(x1))) TRS: a(x1) -> x1 a(x1) -> c(b(b(x1))) b(c(a(x1))) -> a(a(c(x1))) c(x1) -> x1 graph: SCC Processor: #sccs: 0 #rules: 0 #arcs: 0/4