Consider the following premises. For all z_4, if z_4 makes tea, then z_4 is a soldier. For all z_4, z_4 will not make tea. For all z_4, if z_4 were a soldier, then z_4 is making tea. Can we infer the following from them? There is at least one z_4 for which z_4 is a soldier.
 From the fact that for all z_4, if z_4 makes tea, then z_4 is a soldier, and that for all z_4, if z_4 were a soldier, then z_4 is making tea we can infer that for all z_4, z_4 will make tea if and only if z_4 is a soldier. Finally, from the fact that for all z_4, z_4 will make tea if and only if z_4 is a soldier, and that for all z_4, z_4 will not make tea we can infer that for all z_4, z_4 is not a soldier, which contradicts that There is at least one z_4 for which z_4 is a soldier. Therefore, the answer is no.