Consider the following premises. For all y_2, if y_2 drinks water, then y_2 is not a bartender. There is at least one y_2 for which if y_2 drinks water, then y_2 is sleeping. For all y_2, if y_2 sleeps, then y_2 is drinking water. For all y_2, y_2 is a bartender. Can we infer the following from them? There is at least one y_2 for which y_2 will not sleep.
 From the fact that there is at least one y_2 for which if y_2 drinks water, then y_2 is sleeping, and that for all y_2, if y_2 sleeps, then y_2 is drinking water we can infer that there is at least one y_2 for which y_2 will drink water if and only if y_2 will sleep. From the fact that for all y_2, if y_2 drinks water, then y_2 is not a bartender, and that for all y_2, y_2 is a bartender we can infer that for all y_2, y_2 will not drink water. Finally, from the fact that there is at least one y_2 for which y_2 will drink water if and only if y_2 will sleep, and that for all y_2, y_2 will not drink water we can infer that there is at least one y_2 for which y_2 will not sleep. Therefore, the answer is yes.