Consider the following premises. For all x_1, if x_1 were an electrician, then x_1 is a janitor. For all x_1, if x_1 were a janitor, then x_1 is poor. For all x_1, x_1 is not poor. Can we infer the following from them? If we can, name the inference rule being used: For all x_1, x_1 is not an electrician.
 From the fact that for all x_1, if x_1 were a janitor, then x_1 is poor, and that for all x_1, x_1 is not poor we can infer that for all x_1, x_1 is not a janitor via universal modus tollens. Finally, from the fact that for all x_1, if x_1 were an electrician, then x_1 is a janitor, and that for all x_1, x_1 is not a janitor we can infer that for all x_1, x_1 is not an electrician via universal modus tollens. Therefore, the answer is yes.