Consider the following premises. Linda is not working. Linda is working if and only if Mary is taking a plane. It is late if and only if Mary is taking a plane. Can we infer the following from them? If we can, name the inference rule being used: It is not late.
 From the fact that Linda is working if and only if Mary is taking a plane, and that Linda is not working we can infer that Mary is not taking a plane via biconditional elimination. Finally, from the fact that it is late if and only if Mary is taking a plane, and that Mary is not taking a plane we can infer that it is not late via biconditional elimination. Therefore, the answer is yes.