Consider the following premises. q_9 -> r_9. ~r_9 or r. q_2 or q_9. q_2 -> r_9. Can we infer r_4 or r from them? If possible, name the inference rules being used at each step.
 From q_2 -> r_9, q_9 -> r_9, q_2 or q_9 we can infer r_9 via disjunction elimination. From r_9 we can infer r_9 or r_4 via addition. Finally, from r_9 or r_4, ~r_9 or r we can infer r_4 or r via resolution. Therefore, the answer is yes.