Consider the following premises. It is snowing if and only if it is windy. If William reads a book, then it is snowing. If it snows, then William is reading a book. It is not windy. Can we infer the following from them? If we can, name the inference rule being used: William is not reading a book.
 From the fact that it is snowing if and only if it is windy, and that it is not windy we can infer that it is not snowing via biconditional elimination. From the fact that if it snows, then William is reading a book, and that if William reads a book, then it is snowing we can infer that it is snowing if and only if William is reading a book via biconditional introduction. Finally, from the fact that it is snowing if and only if William is reading a book, and that it is not snowing we can infer that William is not reading a book via biconditional elimination. Therefore, the answer is yes.