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