Consider the following premises. q_4 <-> w_1. q_4 -> q. s or u. ~s or w_1. u -> q_4. Can we infer q from them?
 From q_4 <-> w_1 we can infer w_1 -> q_4. From s or u, ~s or w_1 we can infer u or w_1. From u -> q_4, w_1 -> q_4, u or w_1 we can infer q_4. Finally, from q_4 -> q, q_4 we can infer q. Therefore, the answer is yes.