NO Problem: a(a(b(x1))) -> b(b(c(a(a(x1))))) a(c(x1)) -> a(a(x1)) Proof: String Reversal Processor: b(a(a(x1))) -> a(a(c(b(b(x1))))) c(a(x1)) -> a(a(x1)) Unfolding Processor: loop length: 11 terms: b(a(a(a(a(a(a(a(a(x29288))))))))) a(a(c(b(b(a(a(a(a(a(a(x29288))))))))))) a(a(c(b(a(a(c(b(b(a(a(a(a(x29288))))))))))))) a(a(c(b(a(a(c(b(a(a(c(b(b(a(a(x29288))))))))))))))) a(a(c(b(a(a(c(a(a(c(b(b(c(b(b(a(a(x29288))))))))))))))))) a(a(c(b(a(a(a(a(a(c(b(b(c(b(b(a(a(x29288))))))))))))))))) a(a(c(b(a(a(a(a(a(c(b(b(c(b(a(a(c(b(b(x29288))))))))))))))))))) a(a(c(b(a(a(a(a(a(c(b(b(c(a(a(c(b(b(c(b(b(x29288))))))))))))))))))))) a(a(c(b(a(a(a(a(a(c(b(b(a(a(a(c(b(b(c(b(b(x29288))))))))))))))))))))) a(a(c(b(a(a(a(a(a(c(b(a(a(c(b(b(a(c(b(b(c(b(b(x29288))))))))))))))))))))))) a(a(c(b(a(a(a(a(a(c(a(a(c(b(b(c(b(b(a(c(b(b(c(b(b(x29288))))))))))))))))))))))))) context: a(a(c([]))) substitution: x29288 -> c(b(b(c(b(b(a(c(b(b(c(b(b(x29288))))))))))))) Qed