Consider the following premises. It is overcast if and only if Susan is working. Susan is working or it is not overcast. If it is overcast, then Susan is working. Can we infer the following from them? Susan is working if and only if it is overcast.
 From the fact that Susan is working or it is not overcast we can infer that if it is overcast, then Susan is working. From the fact that it is overcast if and only if Susan is working we can infer that if Susan works, then it is overcast. From the fact that if it is overcast, then Susan is working, and that if Susan works, then it is overcast we can infer that it is overcast if and only if Susan is working. From the fact that it is overcast if and only if Susan is working we can infer that if Susan works, then it is overcast. Finally, from the fact that if Susan works, then it is overcast, and that if it is overcast, then Susan is working we can infer that Susan is working if and only if it is overcast. Therefore, the answer is yes.