Consider the following premises. For all x_9, x_9 is a police officer. For all x_9, if x_9 were a police officer, then x_9 is reading a book. For all x_9, if x_9 drives a car, then x_9 is reading a book. For all x_9, if x_9 takes a plane, then x_9 is driving a car. Can we infer the following from them? If we can, name the inference rule being used: Thomas is not reading a book.
 From the fact that for all x_9, x_9 is a police officer we can infer that for all x_9, x_9 is a police officer or x_9 will take a plane via universal addition. From the fact that for all x_9, if x_9 takes a plane, then x_9 is driving a car, and that for all x_9, if x_9 drives a car, then x_9 is reading a book we can infer that for all x_9, if x_9 takes a plane, then x_9 is reading a book via universal transitivity. Finally, from the fact that for all x_9, if x_9 were a police officer, then x_9 is reading a book, that for all x_9, if x_9 takes a plane, then x_9 is reading a book, and that for all x_9, x_9 is a police officer or x_9 will take a plane we can infer that for all x_9, x_9 will read a book via universal disjunction elimination, which contradicts that Thomas is not reading a book. Therefore, the answer is no.