Consider the following premises. If Linda were excited, then Michael is making tea. If it is windy, then Elisabeth is climbing a mountain. If Michael makes tea, then it is windy. If Elisabeth climbs a mountain, then Linda is excited. Can we infer the following from them? If we can, name the inference rule being used: Elisabeth is climbing a mountain if and only if it is windy.
 From the fact that if Linda were excited, then Michael is making tea, and that if Michael makes tea, then it is windy we can infer that if Linda were excited, then it is windy via transitivity. From the fact that if Elisabeth climbs a mountain, then Linda is excited, and that if Linda were excited, then it is windy we can infer that if Elisabeth climbs a mountain, then it is windy via transitivity. Finally, from the fact that if Elisabeth climbs a mountain, then it is windy, and that if it is windy, then Elisabeth is climbing a mountain we can infer that Elisabeth is climbing a mountain if and only if it is windy via biconditional introduction. Therefore, the answer is yes.