Consider the following premises. For all x_6, if x_6 were a janitor, then x_6 is driving a car. For all x_6, if x_6 drives a car, then x_6 is playing squash. For all x_6, x_6 will not play squash. There is at least one x_6 for which x_6 is a mechanic if and only if x_6 is a janitor. For all x_6, if x_6 plays squash, then x_6 is a janitor. Can we infer the following from them? There is at least one x_6 for which x_6 is not a mechanic.
 From the fact that for all x_6, if x_6 were a janitor, then x_6 is driving a car, and that for all x_6, if x_6 drives a car, then x_6 is playing squash we can infer that for all x_6, if x_6 were a janitor, then x_6 is playing squash. From the fact that for all x_6, if x_6 were a janitor, then x_6 is playing squash, and that for all x_6, if x_6 plays squash, then x_6 is a janitor we can infer that for all x_6, x_6 is a janitor if and only if x_6 will play squash. From the fact that for all x_6, x_6 is a janitor if and only if x_6 will play squash, and that for all x_6, x_6 will not play squash we can infer that for all x_6, x_6 is not a janitor. Finally, from the fact that there is at least one x_6 for which x_6 is a mechanic if and only if x_6 is a janitor, and that for all x_6, x_6 is not a janitor we can infer that there is at least one x_6 for which x_6 is not a mechanic. Therefore, the answer is yes.