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