Consider the following premises. Elisabeth is making tea or it is not late. If Charles plays a game, then it is late. If it is late, then Charles is playing a game. Can we infer the following from them? If we can, name the inference rule being used: If Charles plays a game, then Elisabeth is making tea.
 From the fact that if Charles plays a game, then it is late, and that if it is late, then Charles is playing a game we can infer that Charles is playing a game if and only if it is late via biconditional introduction. From the fact that Elisabeth is making tea or it is not late we can infer that if it is late, then Elisabeth is making tea via rewriting. From the fact that Charles is playing a game if and only if it is late we can infer that if Charles plays a game, then it is late via biconditional elimination. Finally, from the fact that if Charles plays a game, then it is late, and that if it is late, then Elisabeth is making tea we can infer that if Charles plays a game, then Elisabeth is making tea via transitivity. Therefore, the answer is yes.