YES Problem: a(b(x1)) -> b(c(a(x1))) b(c(x1)) -> c(b(b(x1))) c(a(x1)) -> a(c(x1)) Proof: String Reversal Processor: b(a(x1)) -> a(c(b(x1))) c(b(x1)) -> b(b(c(x1))) a(c(x1)) -> c(a(x1)) Matrix Interpretation Processor: dim=3 interpretation: [1 0 1] [c](x0) = [0 0 0]x0 [0 0 0] , [1 0 0] [0] [a](x0) = [0 1 1]x0 + [1] [0 0 0] [0], [1 1 0] [b](x0) = [0 1 0]x0 [0 0 1] orientation: [1 1 1] [1] [1 1 1] [0] b(a(x1)) = [0 1 1]x1 + [1] >= [0 0 0]x1 + [1] = a(c(b(x1))) [0 0 0] [0] [0 0 0] [0] [1 1 1] [1 0 1] c(b(x1)) = [0 0 0]x1 >= [0 0 0]x1 = b(b(c(x1))) [0 0 0] [0 0 0] [1 0 1] [0] [1 0 0] a(c(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 = c(a(x1)) [0 0 0] [0] [0 0 0] problem: c(b(x1)) -> b(b(c(x1))) a(c(x1)) -> c(a(x1)) String Reversal Processor: b(c(x1)) -> c(b(b(x1))) c(a(x1)) -> a(c(x1)) Matrix Interpretation Processor: dim=3 interpretation: [1 1 1] [0] [c](x0) = [0 0 0]x0 + [1] [0 1 1] [0], [1 0 0] [0] [a](x0) = [0 0 0]x0 + [1] [0 1 1] [0], [b](x0) = x0 orientation: [1 1 1] [0] [1 1 1] [0] b(c(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = c(b(b(x1))) [0 1 1] [0] [0 1 1] [0] [1 1 1] [1] [1 1 1] [0] c(a(x1)) = [0 0 0]x1 + [1] >= [0 0 0]x1 + [1] = a(c(x1)) [0 1 1] [1] [0 1 1] [1] problem: b(c(x1)) -> c(b(b(x1))) KBO Processor: weight function: w0 = 1 w(c) = 1 w(b) = 0 precedence: b > c problem: Qed