Consider the following premises. There is at least one x_9 for which if x_9 were an artist, then x_9 is driving a car. For all x_9, x_9 is a server if and only if x_9 will drive a car. For all x_9, x_9 is not a server. 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 not an artist.
 From the fact that for all x_9, x_9 is a server if and only if x_9 will drive a car we can infer that for all x_9, if x_9 drives a car, then x_9 is a server via universal biconditional elimination. From the fact that there is at least one x_9 for which if x_9 were an artist, then x_9 is driving a car, and that for all x_9, if x_9 drives a car, then x_9 is a server we can infer that there is at least one x_9 for which if x_9 were an artist, then x_9 is a server via existential transitivity. Finally, from the fact that there is at least one x_9 for which if x_9 were an artist, then x_9 is a server, and that for all x_9, x_9 is not a server we can infer that there is at least one x_9 for which x_9 is not an artist via existential modus tollens. Therefore, the answer is yes.