Consider the following premises. If Barbara were an electrician, then it is windy. It is windy if and only if Barbara is an electrician. Can we infer the following from them? If we can, name the inference rule being used: If is not true that Barbara is an electrician if and only if it is windy.
 From the fact that it is windy if and only if Barbara is an electrician we can infer that if it is windy, then Barbara is an electrician via biconditional elimination. Finally, from the fact that if Barbara were an electrician, then it is windy, and that if it is windy, then Barbara is an electrician we can infer that Barbara is an electrician if and only if it is windy via biconditional introduction, which contradicts that If is not true that Barbara is an electrician if and only if it is windy. Therefore, the answer is no.