Consider the following premises. r_8 -> r. r -> u_3. q_8 -> r_8. u_3 -> q_8. Can we infer r_8 -> u_3 from them? If possible, name the inference rules being used at each step.
 From u_3 -> q_8, q_8 -> r_8 we can infer u_3 -> r_8 via transitivity. Finally, from r_8 -> r, r -> u_3 we can infer r_8 -> u_3 via transitivity. Therefore, the answer is yes.