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