YES Problem: a(a(b(b(x1)))) -> b(b(c(c(a(a(x1)))))) b(b(c(c(x1)))) -> c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) Proof: String Reversal Processor: b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) c(c(b(b(x1)))) -> b(b(b(b(c(c(x1)))))) a(a(b(b(x1)))) -> b(b(c(c(a(a(x1)))))) Matrix Interpretation Processor: dim=3 interpretation: [1 0 0] [c](x0) = [0 1 0]x0 [0 0 0] , [1 0 0] [0] [a](x0) = [0 0 1]x0 + [1] [0 1 0] [0], [1 0 1] [b](x0) = [1 0 0]x0 [0 0 1] orientation: [1 0 2] [2] [1 0 2] [0] b(b(a(a(x1)))) = [1 0 1]x1 + [1] >= [1 0 1]x1 + [1] = a(a(c(c(b(b(x1)))))) [0 0 1] [1] [0 0 0] [1] [1 0 2] [1 0 0] c(c(b(b(x1)))) = [1 0 1]x1 >= [1 0 0]x1 = b(b(b(b(c(c(x1)))))) [0 0 0] [0 0 0] [1 0 2] [0] [1 0 0] a(a(b(b(x1)))) = [1 0 1]x1 + [1] >= [1 0 0]x1 = b(b(c(c(a(a(x1)))))) [0 0 1] [1] [0 0 0] problem: c(c(b(b(x1)))) -> b(b(b(b(c(c(x1)))))) a(a(b(b(x1)))) -> b(b(c(c(a(a(x1)))))) String Reversal Processor: b(b(c(c(x1)))) -> c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) DP Processor: DPs: b#(b(c(c(x1)))) -> b#(x1) b#(b(c(c(x1)))) -> b#(b(x1)) b#(b(c(c(x1)))) -> b#(b(b(x1))) b#(b(c(c(x1)))) -> b#(b(b(b(x1)))) b#(b(a(a(x1)))) -> b#(x1) b#(b(a(a(x1)))) -> b#(b(x1)) TRS: b(b(c(c(x1)))) -> c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) Arctic Interpretation Processor: dimension: 1 interpretation: [b#](x0) = x0, [c](x0) = x0, [a](x0) = 1x0, [b](x0) = x0 orientation: b#(b(c(c(x1)))) = x1 >= x1 = b#(x1) b#(b(c(c(x1)))) = x1 >= x1 = b#(b(x1)) b#(b(c(c(x1)))) = x1 >= x1 = b#(b(b(x1))) b#(b(c(c(x1)))) = x1 >= x1 = b#(b(b(b(x1)))) b#(b(a(a(x1)))) = 2x1 >= x1 = b#(x1) b#(b(a(a(x1)))) = 2x1 >= x1 = b#(b(x1)) b(b(c(c(x1)))) = x1 >= x1 = c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) = 2x1 >= 2x1 = a(a(c(c(b(b(x1)))))) problem: DPs: b#(b(c(c(x1)))) -> b#(x1) b#(b(c(c(x1)))) -> b#(b(x1)) b#(b(c(c(x1)))) -> b#(b(b(x1))) b#(b(c(c(x1)))) -> b#(b(b(b(x1)))) TRS: b(b(c(c(x1)))) -> c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) Arctic Interpretation Processor: dimension: 1 interpretation: [b#](x0) = x0, [c](x0) = 1x0, [a](x0) = 0, [b](x0) = x0 orientation: b#(b(c(c(x1)))) = 2x1 >= x1 = b#(x1) b#(b(c(c(x1)))) = 2x1 >= x1 = b#(b(x1)) b#(b(c(c(x1)))) = 2x1 >= x1 = b#(b(b(x1))) b#(b(c(c(x1)))) = 2x1 >= x1 = b#(b(b(b(x1)))) b(b(c(c(x1)))) = 2x1 >= 2x1 = c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) = 0 >= 0 = a(a(c(c(b(b(x1)))))) problem: DPs: TRS: b(b(c(c(x1)))) -> c(c(b(b(b(b(x1)))))) b(b(a(a(x1)))) -> a(a(c(c(b(b(x1)))))) Qed