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