Consider the following premises. For all x_9, x_9 will work and x_9 will play squash. For all x_9, if x_9 were a taxi driver, then x_9 is not driving a car. For all x_9, if x_9 works, then x_9 is driving a car. For all x_9, if x_9 listens to a song, then x_9 is driving a car. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_9 for which x_9 is a taxi driver.
 From the fact that for all x_9, x_9 will work and x_9 will play squash we can infer that for all x_9, x_9 will work via universal simplification. From the fact that for all x_9, x_9 will work we can infer that for all x_9, x_9 will work or x_9 will listen to a song via universal addition. From the fact that for all x_9, if x_9 works, then x_9 is driving a car, that for all x_9, if x_9 listens to a song, then x_9 is driving a car, and that for all x_9, x_9 will work or x_9 will listen to a song we can infer that for all x_9, x_9 will drive a car via universal disjunction elimination. Finally, from the fact that for all x_9, if x_9 were a taxi driver, then x_9 is not driving a car, and that for all x_9, x_9 will drive a car we can infer that for all x_9, x_9 is not a taxi driver via universal modus tollens, which contradicts that There is at least one x_9 for which x_9 is a taxi driver. Therefore, the answer is no.