Consider the following premises. For all z_2, z_2 will drive a car. For all z_2, z_2 will drink water if and only if z_2 will drive a car. For all z_2, z_2 is a server. Can we infer the following from them? For all z_2, z_2 will drink water and z_2 is a server.
 From the fact that for all z_2, z_2 will drink water if and only if z_2 will drive a car we can infer that for all z_2, if z_2 drives a car, then z_2 is drinking water. From the fact that for all z_2, if z_2 drives a car, then z_2 is drinking water, and that for all z_2, z_2 will drive a car we can infer that for all z_2, z_2 will drink water. Finally, from the fact that for all z_2, z_2 will drink water, and that for all z_2, z_2 is a server we can infer that for all z_2, z_2 will drink water and z_2 is a server. Therefore, the answer is yes.