Consider the following premises. q -> q_4. q_1 -> u. q_4 -> u. q. Can we infer u from them?
 From q -> q_4, q we can infer q_4. From q_4 we can infer q_4 or q_1. Finally, from q_4 -> u, q_1 -> u, q_4 or q_1 we can infer u. Therefore, the answer is yes.