YES Problem: a(a(x1)) -> a(b(c(b(x1)))) b(c(x1)) -> x1 c(b(x1)) -> a(c(x1)) Proof: String Reversal Processor: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) DP Processor: DPs: a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> c#(b(a(x1))) a#(a(x1)) -> b#(c(b(a(x1)))) b#(c(x1)) -> a#(x1) b#(c(x1)) -> c#(a(x1)) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) TDG Processor: DPs: a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> c#(b(a(x1))) a#(a(x1)) -> b#(c(b(a(x1)))) b#(c(x1)) -> a#(x1) b#(c(x1)) -> c#(a(x1)) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) graph: b#(c(x1)) -> a#(x1) -> a#(a(x1)) -> b#(c(b(a(x1)))) b#(c(x1)) -> a#(x1) -> a#(a(x1)) -> c#(b(a(x1))) b#(c(x1)) -> a#(x1) -> a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) -> b#(c(x1)) -> c#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) -> b#(c(x1)) -> a#(x1) a#(a(x1)) -> b#(a(x1)) -> b#(c(x1)) -> c#(a(x1)) a#(a(x1)) -> b#(a(x1)) -> b#(c(x1)) -> a#(x1) SCC Processor: #sccs: 1 #rules: 3 #arcs: 7/25 DPs: b#(c(x1)) -> a#(x1) a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) Arctic Interpretation Processor: dimension: 2 usable rules: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) interpretation: [b#](x0) = [0 1]x0 + [0], [-& 0 ] [0] [b](x0) = [0 1 ]x0 + [1], [a#](x0) = [0 -&]x0, [1 0 ] [1] [a](x0) = [0 -&]x0 + [0], [-& 0 ] [0 ] [c](x0) = [0 -&]x0 + [-&] orientation: b#(c(x1)) = [1 0]x1 + [0] >= [0 -&]x1 = a#(x1) a#(a(x1)) = [1 0]x1 + [1] >= [1 0]x1 + [1] = b#(a(x1)) a#(a(x1)) = [1 0]x1 + [1] >= [1 0]x1 + [1] = b#(c(b(a(x1)))) [2 1] [2] [0 -&] [0] a(a(x1)) = [1 0]x1 + [1] >= [1 0 ]x1 + [1] = b(c(b(a(x1)))) [0 1 ] [1] c(b(x1)) = [-& 0 ]x1 + [0] >= x1 = x1 [0 -&] [0] [0 -&] [0] b(c(x1)) = [1 0 ]x1 + [1] >= [1 0 ]x1 + [1] = c(a(x1)) problem: DPs: a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) Restore Modifier: DPs: a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) EDG Processor: DPs: a#(a(x1)) -> b#(a(x1)) a#(a(x1)) -> b#(c(b(a(x1)))) TRS: a(a(x1)) -> b(c(b(a(x1)))) c(b(x1)) -> x1 b(c(x1)) -> c(a(x1)) graph: SCC Processor: #sccs: 0 #rules: 0 #arcs: 0/4