Consider the following premises. If it is sunny, then Sarah is a bartender. Charles is a taxi driver or Sarah is not a bartender. It is sunny. Can we infer the following from them? Charles is not a taxi driver.
 From the fact that Charles is a taxi driver or Sarah is not a bartender we can infer that if Sarah were a bartender, then Charles is a taxi driver. From the fact that if it is sunny, then Sarah is a bartender, and that if Sarah were a bartender, then Charles is a taxi driver we can infer that if it is sunny, then Charles is a taxi driver. Finally, from the fact that if it is sunny, then Charles is a taxi driver, and that it is sunny we can infer that Charles is a taxi driver, which contradicts that Charles is not a taxi driver. Therefore, the answer is no.