Consider the following premises. William is rich. Sarah is making tea or William is not rich. If Sarah makes tea, then William is rich. Can we infer the following from them? If we can, name the inference rule being used: Sarah is making tea.
 From the fact that Sarah is making tea or William is not rich we can infer that if William were rich, then Sarah is making tea via rewriting. From the fact that if William were rich, then Sarah is making tea, and that if Sarah makes tea, then William is rich we can infer that William is rich if and only if Sarah is making tea via biconditional introduction. From the fact that William is rich if and only if Sarah is making tea we can infer that if William were rich, then Sarah is making tea via biconditional elimination. Finally, from the fact that if William were rich, then Sarah is making tea, and that William is rich we can infer that Sarah is making tea via modus ponens. Therefore, the answer is yes.