Consider the following premises. For all x_9, if x_9 reads a book, then x_9 is taking a plane. For all x_9, x_9 will not take a plane. For all x_9, if x_9 were a nurse, then x_9 is curious. For all x_9, x_9 will read a book if and only if x_9 is curious. Can we infer the following from them? If we can, name the inference rule being used: For all x_9, x_9 is not a nurse.
 From the fact that for all x_9, if x_9 reads a book, then x_9 is taking a plane, and that for all x_9, x_9 will not take a plane we can infer that for all x_9, x_9 will not read a book via universal modus tollens. From the fact that for all x_9, x_9 will read a book if and only if x_9 is curious we can infer that for all x_9, if x_9 were curious, then x_9 is reading a book via universal biconditional elimination. From the fact that for all x_9, if x_9 were a nurse, then x_9 is curious, and that for all x_9, if x_9 were curious, then x_9 is reading a book we can infer that for all x_9, if x_9 were a nurse, then x_9 is reading a book via universal transitivity. Finally, from the fact that for all x_9, if x_9 were a nurse, then x_9 is reading a book, and that for all x_9, x_9 will not read a book we can infer that for all x_9, x_9 is not a nurse via universal modus tollens. Therefore, the answer is yes.