Consider the following premises. For all x_6, x_6 is a server or x_6 will drive a car. For all x_6, x_6 is a cashier or x_6 is not a server. For all x_6, if x_6 drives a car, then x_6 is a cashier. For all x_6, if x_6 were a janitor, then x_6 is not a cashier. Can we infer the following from them? For all x_6, x_6 is not a janitor.
 From the fact that for all x_6, x_6 is a cashier or x_6 is not a server we can infer that for all x_6, if x_6 were a server, then x_6 is a cashier. From the fact that for all x_6, if x_6 were a server, then x_6 is a cashier, that for all x_6, if x_6 drives a car, then x_6 is a cashier, and that for all x_6, x_6 is a server or x_6 will drive a car we can infer that for all x_6, x_6 is a cashier. Finally, from the fact that for all x_6, if x_6 were a janitor, then x_6 is not a cashier, and that for all x_6, x_6 is a cashier we can infer that for all x_6, x_6 is not a janitor. Therefore, the answer is yes.