Consider the following premises. ~q_12 -> p. p -> t. u <-> q_12. ~u. Can we infer t from them?
 From u <-> q_12, ~u we can infer ~q_12. From ~q_12 -> p, p -> t we can infer ~q_12 -> t. Finally, from ~q_12 -> t, ~q_12 we can infer t. Therefore, the answer is yes.