Consider the following premises. q_9. q <-> p_9. p_9 -> q. p_9 -> ~q_9. Can we infer ~q from them? If possible, name the inference rules being used at each step.
 From p_9 -> ~q_9, q_9 we can infer ~p_9 via modus tollens. From q <-> p_9 we can infer q -> p_9 via biconditional elimination. From q -> p_9, p_9 -> q we can infer q <-> p_9 via biconditional introduction. Finally, from q <-> p_9, ~p_9 we can infer ~q via biconditional elimination. Therefore, the answer is yes.