Consider the following premises. There is at least one y for which if y goes running, then y is not a janitor. For all y, y is an electrician. For all y, if y were an electrician, then y is a janitor. Can we infer the following from them? If we can, name the inference rule being used: There is at least one y for which y will not go running.
 From the fact that for all y, if y were an electrician, then y is a janitor, and that for all y, y is an electrician we can infer that for all y, y is a janitor via universal modus ponens. Finally, from the fact that there is at least one y for which if y goes running, then y is not a janitor, and that for all y, y is a janitor we can infer that there is at least one y for which y will not go running via existential modus tollens. Therefore, the answer is yes.