Consider the following premises. t -> q_6. q_6 -> t. p_3 <-> t. ~p_3. Can we infer ~q_6 from them? If possible, name the inference rules being used at each step.
 From t -> q_6, q_6 -> t we can infer t <-> q_6 via biconditional introduction. From p_3 <-> t, ~p_3 we can infer ~t via biconditional elimination. Finally, from t <-> q_6, ~t we can infer ~q_6 via biconditional elimination. Therefore, the answer is yes.