Consider the following premises. For all x_12, x_12 will read a book if and only if x_12 will play squash. For all x_12, x_12 will drive a car or x_12 will not play squash. For all x_12, if x_12 plays squash, then x_12 is reading a book. For all x_12, x_12 will not drive a car. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_12 for which x_12 will read a book.
 From the fact that for all x_12, x_12 will read a book if and only if x_12 will play squash we can infer that for all x_12, if x_12 reads a book, then x_12 is playing squash via universal biconditional elimination. From the fact that for all x_12, if x_12 reads a book, then x_12 is playing squash, and that for all x_12, if x_12 plays squash, then x_12 is reading a book we can infer that for all x_12, x_12 will read a book if and only if x_12 will play squash via universal biconditional introduction. From the fact that for all x_12, x_12 will drive a car or x_12 will not play squash we can infer that for all x_12, if x_12 plays squash, then x_12 is driving a car via universal rewriting. From the fact that for all x_12, if x_12 plays squash, then x_12 is driving a car, and that for all x_12, x_12 will not drive a car we can infer that for all x_12, x_12 will not play squash via universal modus tollens. Finally, from the fact that for all x_12, x_12 will read a book if and only if x_12 will play squash, and that for all x_12, x_12 will not play squash we can infer that for all x_12, x_12 will not read a book via universal biconditional elimination, which contradicts that There is at least one x_12 for which x_12 will read a book. Therefore, the answer is no.