YES Problem: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) c(d(x1)) -> d(c(b(a(x1)))) Proof: String Reversal Processor: a(b(a(x1))) -> c(b(x1)) b(b(b(x1))) -> b(c(x1)) c(x1) -> b(a(x1)) d(c(x1)) -> a(b(c(d(x1)))) Matrix Interpretation Processor: dim=3 interpretation: [1 0 1] [0] [d](x0) = [1 1 1]x0 + [1] [1 1 1] [0], [1 0 0] [0] [c](x0) = [1 1 1]x0 + [1] [1 0 1] [1], [1 0 0] [b](x0) = [1 0 0]x0 [0 0 0] , [1 0 0] [0] [a](x0) = [1 1 0]x0 + [1] [1 1 0] [1] orientation: [1 0 0] [0] [1 0 0] [0] a(b(a(x1))) = [2 0 0]x1 + [1] >= [2 0 0]x1 + [1] = c(b(x1)) [2 0 0] [1] [1 0 0] [1] [1 0 0] [1 0 0] b(b(b(x1))) = [1 0 0]x1 >= [1 0 0]x1 = b(c(x1)) [0 0 0] [0 0 0] [1 0 0] [0] [1 0 0] c(x1) = [1 1 1]x1 + [1] >= [1 0 0]x1 = b(a(x1)) [1 0 1] [1] [0 0 0] [2 0 1] [1] [1 0 1] [0] d(c(x1)) = [3 1 2]x1 + [3] >= [2 0 2]x1 + [1] = a(b(c(d(x1)))) [3 1 2] [2] [2 0 2] [1] problem: a(b(a(x1))) -> c(b(x1)) b(b(b(x1))) -> b(c(x1)) c(x1) -> b(a(x1)) String Reversal Processor: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) DP Processor: DPs: a#(b(a(x1))) -> c#(x1) a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> b#(x1) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) TDG Processor: DPs: a#(b(a(x1))) -> c#(x1) a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> b#(x1) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) graph: b#(b(b(x1))) -> c#(b(x1)) -> c#(x1) -> a#(b(x1)) b#(b(b(x1))) -> c#(b(x1)) -> c#(x1) -> b#(x1) c#(x1) -> b#(x1) -> b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(c(x1)) c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> c#(x1) a#(b(a(x1))) -> b#(c(x1)) -> b#(b(b(x1))) -> c#(b(x1)) a#(b(a(x1))) -> c#(x1) -> c#(x1) -> a#(b(x1)) a#(b(a(x1))) -> c#(x1) -> c#(x1) -> b#(x1) Arctic Interpretation Processor: dimension: 1 interpretation: [b#](x0) = -2x0 + 0, [c#](x0) = x0 + 1, [a#](x0) = -2x0 + 0, [c](x0) = 4x0 + 3, [b](x0) = 2x0 + 1, [a](x0) = 2x0 + 1 orientation: a#(b(a(x1))) = 2x1 + 1 >= x1 + 1 = c#(x1) a#(b(a(x1))) = 2x1 + 1 >= 2x1 + 1 = b#(c(x1)) b#(b(b(x1))) = 2x1 + 1 >= 2x1 + 1 = c#(b(x1)) c#(x1) = x1 + 1 >= -2x1 + 0 = b#(x1) c#(x1) = x1 + 1 >= x1 + 0 = a#(b(x1)) a(b(a(x1))) = 6x1 + 5 >= 6x1 + 5 = b(c(x1)) b(b(b(x1))) = 6x1 + 5 >= 6x1 + 5 = c(b(x1)) c(x1) = 4x1 + 3 >= 4x1 + 3 = a(b(x1)) problem: DPs: a#(b(a(x1))) -> c#(x1) a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) EDG Processor: DPs: a#(b(a(x1))) -> c#(x1) a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) graph: b#(b(b(x1))) -> c#(b(x1)) -> c#(x1) -> a#(b(x1)) c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> c#(x1) c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(c(x1)) a#(b(a(x1))) -> b#(c(x1)) -> b#(b(b(x1))) -> c#(b(x1)) a#(b(a(x1))) -> c#(x1) -> c#(x1) -> a#(b(x1)) Arctic Interpretation Processor: dimension: 2 interpretation: [b#](x0) = [-& 0 ]x0 + [2], [c#](x0) = [-& 1 ]x0 + [0], [a#](x0) = [-& 0 ]x0 + [0], [0 1 ] [1] [c](x0) = [-& 2 ]x0 + [1], [0 0 ] [0] [b](x0) = [-& 1 ]x0 + [0], [0 0 ] [1] [a](x0) = [-& 1 ]x0 + [1] orientation: a#(b(a(x1))) = [-& 2 ]x1 + [2] >= [-& 1 ]x1 + [0] = c#(x1) a#(b(a(x1))) = [-& 2 ]x1 + [2] >= [-& 2 ]x1 + [2] = b#(c(x1)) b#(b(b(x1))) = [-& 2 ]x1 + [2] >= [-& 2 ]x1 + [1] = c#(b(x1)) c#(x1) = [-& 1 ]x1 + [0] >= [-& 1 ]x1 + [0] = a#(b(x1)) [0 2 ] [2] [0 2 ] [1] a(b(a(x1))) = [-& 3 ]x1 + [3] >= [-& 3 ]x1 + [2] = b(c(x1)) [0 2 ] [1] [0 2 ] [1] b(b(b(x1))) = [-& 3 ]x1 + [2] >= [-& 3 ]x1 + [2] = c(b(x1)) [0 1 ] [1] [0 1 ] [1] c(x1) = [-& 2 ]x1 + [1] >= [-& 2 ]x1 + [1] = a(b(x1)) problem: DPs: a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) EDG Processor: DPs: a#(b(a(x1))) -> b#(c(x1)) b#(b(b(x1))) -> c#(b(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) graph: b#(b(b(x1))) -> c#(b(x1)) -> c#(x1) -> a#(b(x1)) c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(c(x1)) a#(b(a(x1))) -> b#(c(x1)) -> b#(b(b(x1))) -> c#(b(x1)) Arctic Interpretation Processor: dimension: 3 interpretation: [b#](x0) = [1 1 0]x0 + [0], [c#](x0) = [1 1 1]x0 + [1], [a#](x0) = [0 1 1]x0 + [0], [0 0 1] [0] [c](x0) = [0 0 1]x0 + [0] [1 0 0] [1], [1 0 0 ] [1 ] [b](x0) = [-& -& 0 ]x0 + [-&] [0 -& -&] [0 ], [-& 1 0 ] [0] [a](x0) = [-& 1 0 ]x0 + [0] [0 0 1 ] [0] orientation: a#(b(a(x1))) = [1 2 2]x1 + [1] >= [1 1 2]x1 + [1] = b#(c(x1)) b#(b(b(x1))) = [3 2 2]x1 + [3] >= [2 1 1]x1 + [2] = c#(b(x1)) c#(x1) = [1 1 1]x1 + [1] >= [1 0 1]x1 + [1] = a#(b(x1)) [1 1 2] [1] [1 1 2] [1] a(b(a(x1))) = [1 1 2]x1 + [1] >= [1 0 0]x1 + [1] = b(c(x1)) [0 2 1] [1] [0 0 1] [0] [3 2 2] [3] [1 0 0] [1] b(b(b(x1))) = [1 0 0]x1 + [1] >= [1 0 0]x1 + [1] = c(b(x1)) [2 1 1] [2] [2 1 1] [2] [0 0 1] [0] [0 -& 1 ] [0] c(x1) = [0 0 1]x1 + [0] >= [0 -& 1 ]x1 + [0] = a(b(x1)) [1 0 0] [1] [1 0 0 ] [1] problem: DPs: a#(b(a(x1))) -> b#(c(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) EDG Processor: DPs: a#(b(a(x1))) -> b#(c(x1)) c#(x1) -> a#(b(x1)) TRS: a(b(a(x1))) -> b(c(x1)) b(b(b(x1))) -> c(b(x1)) c(x1) -> a(b(x1)) graph: c#(x1) -> a#(b(x1)) -> a#(b(a(x1))) -> b#(c(x1)) SCC Processor: #sccs: 0 #rules: 0 #arcs: 1/4