Consider the following premises. Susan is not a bartender if and only if Jennifer is working. It is not overcast. If Susan were a bartender, then it is overcast. Can we infer the following from them? Jennifer is not working.
 From the fact that if Susan were a bartender, then it is overcast, and that it is not overcast we can infer that Susan is not a bartender. From the fact that Susan is not a bartender if and only if Jennifer is working we can infer that if Susan were not a bartender, then Jennifer is working. Finally, from the fact that if Susan were not a bartender, then Jennifer is working, and that Susan is not a bartender we can infer that Jennifer is working, which contradicts that Jennifer is not working. Therefore, the answer is no.