Consider the following premises. t or ~q_9. t -> q_9. q_9 -> t. Can we infer ~(t <-> q_9) from them?
 From t or ~q_9 we can infer q_9 -> t. Finally, from t -> q_9, q_9 -> t we can infer t <-> q_9, which contradicts ~(t <-> q_9). Therefore, the answer is no.