Consider the following premises. Susan is not a janitor. For all x_12, x_12 will make tea if and only if x_12 is a janitor. Susan is making tea or Sarah is not running. Can we infer the following from them? If we can, name the inference rule being used: Sarah is not running.
 From the fact that for all x_12, x_12 will make tea if and only if x_12 is a janitor we can infer that Susan is making tea if and only if Susan is a janitor via universal instantiation. From the fact that Susan is making tea or Sarah is not running we can infer that if Sarah goes running, then Susan is making tea via rewriting. From the fact that Susan is making tea if and only if Susan is a janitor, and that Susan is not a janitor we can infer that Susan is not making tea via biconditional elimination. Finally, from the fact that if Sarah goes running, then Susan is making tea, and that Susan is not making tea we can infer that Sarah is not running via modus tollens. Therefore, the answer is yes.