Consider the following premises. For all z_3, z_3 is not a soldier. For all z_3, z_3 will play squash if and only if z_3 will make tea. For all z_3, z_3 will play squash if and only if z_3 is a soldier. Can we infer the following from them? If we can, name the inference rule being used: There is at least one z_3 for which z_3 will make tea.
 From the fact that for all z_3, z_3 will play squash if and only if z_3 will make tea we can infer that for all z_3, if z_3 makes tea, then z_3 is playing squash via universal biconditional elimination. From the fact that for all z_3, z_3 will play squash if and only if z_3 is a soldier, and that for all z_3, z_3 is not a soldier we can infer that for all z_3, z_3 will not play squash via universal biconditional elimination. Finally, from the fact that for all z_3, if z_3 makes tea, then z_3 is playing squash, and that for all z_3, z_3 will not play squash we can infer that for all z_3, z_3 will not make tea via universal modus tollens, which contradicts that There is at least one z_3 for which z_3 will make tea. Therefore, the answer is no.