Consider the following premises. For all z, z will drink water if and only if z will read a book. For all z, z is not a police officer. For all z, if z were an artist, then z is reading a book. For all z, z will drink water if and only if z is a police officer. Can we infer the following from them? If we can, name the inference rule being used: There is at least one z for which z is an artist.
 From the fact that for all z, z will drink water if and only if z is a police officer, and that for all z, z is not a police officer we can infer that for all z, z will not drink water via universal biconditional elimination. From the fact that for all z, z will drink water if and only if z will read a book, and that for all z, z will not drink water we can infer that for all z, z will not read a book via universal biconditional elimination. Finally, from the fact that for all z, if z were an artist, then z is reading a book, and that for all z, z will not read a book we can infer that for all z, z is not an artist via universal modus tollens, which contradicts that There is at least one z for which z is an artist. Therefore, the answer is no.