Consider the following premises. p_9 or ~q_9. p_5 <-> q_9. p_9 -> q_9. ~p_5. Can we infer ~p_9 from them? If possible, name the inference rules being used at each step.
 From p_9 or ~q_9 we can infer q_9 -> p_9 via rewriting. From p_5 <-> q_9, ~p_5 we can infer ~q_9 via biconditional elimination. From q_9 -> p_9, p_9 -> q_9 we can infer q_9 <-> p_9 via biconditional introduction. Finally, from q_9 <-> p_9, ~q_9 we can infer ~p_9 via biconditional elimination. Therefore, the answer is yes.