Consider the following premises. P_9(a_9) -> u_1. forall x_9: P_9(x_9). Can we infer u_1 from them?
 From forall x_9: P_9(x_9) we can infer P_9(a_9). Finally, from P_9(a_9) -> u_1, P_9(a_9) we can infer u_1. Therefore, the answer is yes.