Consider the following premises. p_2 -> q_7. u_3 or ~q_7. p_2 or ~s. Can we infer s -> u_3 from them? If possible, name the inference rules being used at each step.
 From p_2 or ~s we can infer s -> p_2 via rewriting. From u_3 or ~q_7 we can infer q_7 -> u_3 via rewriting. From s -> p_2, p_2 -> q_7 we can infer s -> q_7 via transitivity. Finally, from s -> q_7, q_7 -> u_3 we can infer s -> u_3 via transitivity. Therefore, the answer is yes.