Consider the following premises. If Barbara works, then Linda is writing a letter. It is windy if and only if Linda is writing a letter. If it is windy, then Barbara is working. Can we infer the following from them? If we can, name the inference rule being used: The fact that it is windy does not imply that Linda is writing a letter.
 From the fact that it is windy if and only if Linda is writing a letter we can infer that if Linda writes a letter, then it is windy via biconditional elimination. Finally, from the fact that if it is windy, then Barbara is working, and that if Barbara works, then Linda is writing a letter we can infer that if it is windy, then Linda is writing a letter via transitivity, which contradicts that The fact that it is windy does not imply that Linda is writing a letter. Therefore, the answer is no.