Consider the following premises. u_4 -> q_9. p_9 <-> q_9. p_9 -> u_4. Can we infer ~(p_9 <-> u_4) from them?
 From p_9 <-> q_9 we can infer q_9 -> p_9. From u_4 -> q_9, q_9 -> p_9 we can infer u_4 -> p_9. Finally, from p_9 -> u_4, u_4 -> p_9 we can infer p_9 <-> u_4, which contradicts ~(p_9 <-> u_4). Therefore, the answer is no.