Consider the following premises. q_1 -> r_3. q_1. w -> r_3. Can we infer r_3 or q from them? If possible, name the inference rules being used at each step.
 From q_1 we can infer q_1 or w via addition. From q_1 -> r_3, w -> r_3, q_1 or w we can infer r_3 via disjunction elimination. Finally, from r_3 we can infer r_3 or q via addition. Therefore, the answer is yes.