Consider the following premises. If it is late, then James is a carpenter. Jessica is taking a plane or Barbara is not an office clerk. It is late if and only if Jessica is taking a plane. Can we infer the following from them? If Barbara were an office clerk, then James is a carpenter.
 From the fact that it is late if and only if Jessica is taking a plane we can infer that if Jessica takes a plane, then it is late. From the fact that Jessica is taking a plane or Barbara is not an office clerk we can infer that if Barbara were an office clerk, then Jessica is taking a plane. From the fact that if Jessica takes a plane, then it is late, and that if it is late, then James is a carpenter we can infer that if Jessica takes a plane, then James is a carpenter. Finally, from the fact that if Barbara were an office clerk, then Jessica is taking a plane, and that if Jessica takes a plane, then James is a carpenter we can infer that if Barbara were an office clerk, then James is a carpenter. Therefore, the answer is yes.