Consider the following premises. w_1 -> ~q_2. u_4 -> q. q -> w_1. q_2. Can we infer ~u_4 from them?
 From w_1 -> ~q_2, q_2 we can infer ~w_1. From q -> w_1, ~w_1 we can infer ~q. Finally, from u_4 -> q, ~q we can infer ~u_4. Therefore, the answer is yes.