Consider the following premises. For all x_8, if x_8 works, then x_8 is a janitor. For all x_8, x_8 is not a doctor. For all x_8, x_8 is a janitor if and only if x_8 is a doctor. For all x_8, if x_8 plays squash, then x_8 is working. Can we infer the following from them? For all x_8, x_8 will not play squash.
 From the fact that for all x_8, x_8 is a janitor if and only if x_8 is a doctor, and that for all x_8, x_8 is not a doctor we can infer that for all x_8, x_8 is not a janitor. From the fact that for all x_8, if x_8 works, then x_8 is a janitor, and that for all x_8, x_8 is not a janitor we can infer that for all x_8, x_8 will not work. Finally, from the fact that for all x_8, if x_8 plays squash, then x_8 is working, and that for all x_8, x_8 will not work we can infer that for all x_8, x_8 will not play squash. Therefore, the answer is yes.