Consider the following premises. u -> t. t -> u. ~u. t -> u. Can we infer t from them?
 From u -> t, t -> u we can infer u <-> t. From u <-> t we can infer u -> t. From t -> u, u -> t we can infer t <-> u. Finally, from t <-> u, ~u we can infer ~t, which contradicts t. Therefore, the answer is no.