Consider the following premises. p <-> p_2. t -> q_7. p_2 -> t. ~q_7. Can we infer ~p from them? If possible, name the inference rules being used at each step.
 From t -> q_7, ~q_7 we can infer ~t via modus tollens. From p_2 -> t, ~t we can infer ~p_2 via modus tollens. Finally, from p <-> p_2, ~p_2 we can infer ~p via biconditional elimination. Therefore, the answer is yes.