Consider the following premises. For all x_6, x_6 will not read a book. For all x_6, if x_6 were a police officer, then x_6 is a nurse. For all x_6, if x_6 were a nurse, then x_6 is a police officer. There is at least one x_6 for which x_6 will read a book if and only if x_6 is a nurse. Can we infer the following from them? If we can, name the inference rule being used: For all x_6, if x_6 were a nurse, then x_6 is a police officer.
That is one of the premises. Therefore, the answer is yes.