Consider the following premises. ~s_1 or r_13. r_1 or ~r_10. s_1 or u_2. ~r_13 or q. q -> r_1. ~u_2 or r_10. Can we infer r_1 from them? If possible, name the inference rules being used at each step.
 From s_1 or u_2, ~s_1 or r_13 we can infer u_2 or r_13 via resolution. From u_2 or r_13, ~u_2 or r_10 we can infer r_13 or r_10 via resolution. From r_1 or ~r_10 we can infer r_10 -> r_1 via rewriting. From r_13 or r_10, ~r_13 or q we can infer r_10 or q via resolution. Finally, from r_10 -> r_1, q -> r_1, r_10 or q we can infer r_1 via disjunction elimination. Therefore, the answer is yes.