Consider the following premises. For all x_12, x_12 will drink water and x_12 will sleep. For all x_12, if x_12 plays tennis, then x_12 is a cashier. There is at least one x_12 for which if x_12 drinks water, then x_12 is playing tennis. Can we infer the following from them? There is at least one x_12 for which x_12 is a cashier.
 From the fact that for all x_12, x_12 will drink water and x_12 will sleep we can infer that for all x_12, x_12 will drink water. From the fact that there is at least one x_12 for which if x_12 drinks water, then x_12 is playing tennis, and that for all x_12, x_12 will drink water we can infer that there is at least one x_12 for which x_12 will play tennis. Finally, from the fact that for all x_12, if x_12 plays tennis, then x_12 is a cashier, and that there is at least one x_12 for which x_12 will play tennis we can infer that there is at least one x_12 for which x_12 is a cashier. Therefore, the answer is yes.