Consider the following premises. If John were curious, then Richard is an electrician. If Richard were an electrician, then John is curious. If John were curious, then Richard is an electrician. Can we infer the following from them? If we can, name the inference rule being used: John is curious if and only if Richard is an electrician.
 From the fact that if Richard were an electrician, then John is curious, and that if John were curious, then Richard is an electrician we can infer that Richard is an electrician if and only if John is curious via biconditional introduction. From the fact that Richard is an electrician if and only if John is curious we can infer that if Richard were an electrician, then John is curious via biconditional elimination. Finally, from the fact that if John were curious, then Richard is an electrician, and that if Richard were an electrician, then John is curious we can infer that John is curious if and only if Richard is an electrician via biconditional introduction. Therefore, the answer is yes.