Consider the following premises. Karen is drinking water. If Karen drinks water, then Karen is reading a book. It is windy if and only if Karen is reading a book. Can we infer the following from them? If we can, name the inference rule being used: It is windy.
 From the fact that it is windy if and only if Karen is reading a book we can infer that if Karen reads a book, then it is windy via biconditional elimination. From the fact that if Karen drinks water, then Karen is reading a book, and that Karen is drinking water we can infer that Karen is reading a book via modus ponens. Finally, from the fact that if Karen reads a book, then it is windy, and that Karen is reading a book we can infer that it is windy via modus ponens. Therefore, the answer is yes.