Consider the following premises. ~p. s -> q_10. p <-> q_10. q_10 -> u. u -> s. Can we infer ~u from them?
 From p <-> q_10, ~p we can infer ~q_10. From u -> s, s -> q_10 we can infer u -> q_10. From u -> q_10, q_10 -> u we can infer u <-> q_10. Finally, from u <-> q_10, ~q_10 we can infer ~u. Therefore, the answer is yes.