NO Problem: a(b(b(x1))) -> b(b(a(a(x1)))) a(a(x1)) -> b(x1) Proof: Unfolding Processor: loop length: 6 terms: a(b(b(b(b(b(b(x1043))))))) b(b(a(a(b(b(b(b(x1043)))))))) b(b(a(b(b(a(a(b(b(x1043))))))))) b(b(a(b(b(a(b(b(a(a(x1043)))))))))) b(b(a(b(b(b(b(a(a(a(a(x1043))))))))))) b(b(a(b(b(b(b(b(a(a(x1043)))))))))) context: b(b([])) substitution: x1043 -> x1043 Qed