NO Problem: a(x1) -> x1 a(b(x1)) -> b(c(b(a(c(a(a(x1))))))) c(c(x1)) -> x1 Proof: String Reversal Processor: a(x1) -> x1 b(a(x1)) -> a(a(c(a(b(c(b(x1))))))) c(c(x1)) -> x1 Unfolding Processor: loop length: 10 terms: b(a(a(a(x183026)))) a(a(c(a(b(c(b(a(a(x183026))))))))) a(a(c(a(b(c(a(a(c(a(b(c(b(a(x183026)))))))))))))) a(a(c(a(b(c(a(c(a(b(c(b(a(x183026))))))))))))) a(a(c(a(b(c(c(a(b(c(b(a(x183026)))))))))))) a(a(c(a(b(a(b(c(b(a(x183026)))))))))) a(a(c(a(b(a(b(c(a(a(c(a(b(c(b(x183026))))))))))))))) a(a(c(a(b(a(b(c(a(c(a(b(c(b(x183026)))))))))))))) a(a(c(a(b(a(b(c(c(a(b(c(b(x183026))))))))))))) a(a(c(a(b(a(b(a(b(c(b(x183026))))))))))) context: a(a(c(a([])))) substitution: x183026 -> c(a(b(c(b(b(c(b(x183026)))))))) Qed