Consider the following premises. w_1 <-> q. w_1 -> r. Can we infer q -> r from them? If possible, name the inference rules being used at each step.
 From w_1 <-> q we can infer q -> w_1 via biconditional elimination. Finally, from q -> w_1, w_1 -> r we can infer q -> r via transitivity. Therefore, the answer is yes.