Consider the following premises. There is at least one x_6 for which if x_6 were a police officer, then x_6 is sleeping. For all x_6, x_6 will sleep if and only if x_6 is fast. For all x_6, x_6 is a police officer. Can we infer the following from them? There is at least one x_6 for which x_6 will sleep.
 From the fact that for all x_6, x_6 will sleep if and only if x_6 is fast we can infer that for all x_6, if x_6 were fast, then x_6 is sleeping. From the fact that for all x_6, x_6 is a police officer we can infer that for all x_6, x_6 is a police officer or x_6 is fast. Finally, from the fact that there is at least one x_6 for which if x_6 were a police officer, then x_6 is sleeping, that for all x_6, if x_6 were fast, then x_6 is sleeping, and that for all x_6, x_6 is a police officer or x_6 is fast we can infer that there is at least one x_6 for which x_6 will sleep. Therefore, the answer is yes.