Consider the following premises. If Patricia takes a plane, then it is sunny. Patricia is taking a plane if and only if Joseph is a taxi driver. It is not sunny. Can we infer the following from them? Joseph is a taxi driver.
 From the fact that Patricia is taking a plane if and only if Joseph is a taxi driver we can infer that if Joseph were a taxi driver, then Patricia is taking a plane. From the fact that if Joseph were a taxi driver, then Patricia is taking a plane, and that if Patricia takes a plane, then it is sunny we can infer that if Joseph were a taxi driver, then it is sunny. Finally, from the fact that if Joseph were a taxi driver, then it is sunny, and that it is not sunny we can infer that Joseph is not a taxi driver, which contradicts that Joseph is a taxi driver. Therefore, the answer is no.