Consider the following premises. u_4 <-> q_9. u_4 or ~q_9. ~q_9. Can we infer u_4 from them?
 From u_4 or ~q_9 we can infer q_9 -> u_4. From u_4 <-> q_9 we can infer u_4 -> q_9. From u_4 -> q_9, q_9 -> u_4 we can infer u_4 <-> q_9. Finally, from u_4 <-> q_9, ~q_9 we can infer ~u_4, which contradicts u_4. Therefore, the answer is no.