Consider the following premises. ~q_8. u_3 -> p_8. p_8 <-> q_8. Can we infer ~u_3 from them? If possible, name the inference rules being used at each step.
 From p_8 <-> q_8 we can infer p_8 -> q_8 via biconditional elimination. From u_3 -> p_8, p_8 -> q_8 we can infer u_3 -> q_8 via transitivity. Finally, from u_3 -> q_8, ~q_8 we can infer ~u_3 via modus tollens. Therefore, the answer is yes.