Consider the following premises. q_13. w_1 <-> q_13. r. Can we infer r and w_1 from them? If possible, name the inference rules being used at each step.
 From w_1 <-> q_13 we can infer q_13 -> w_1 via biconditional elimination. From q_13 -> w_1, q_13 we can infer w_1 via modus ponens. Finally, from r, w_1 we can infer r and w_1 via conjunction. Therefore, the answer is yes.