Consider the following premises. Jessica is not a janitor. If Richard were not a taxi driver, then it is cloudy. If Richard were a taxi driver, then Jessica is a janitor. Can we infer the following from them? If we can, name the inference rule being used: It is cloudy or Barbara is driving a car.
 From the fact that if Richard were a taxi driver, then Jessica is a janitor, and that Jessica is not a janitor we can infer that Richard is not a taxi driver via modus tollens. From the fact that if Richard were not a taxi driver, then it is cloudy, and that Richard is not a taxi driver we can infer that it is cloudy via modus ponens. Finally, from the fact that it is cloudy we can infer that it is cloudy or Barbara is driving a car via addition. Therefore, the answer is yes.