Consider the following premises. If William makes tea, then Linda is playing a game. If it is sunny, then William is making tea. Robert is not running. Linda is playing a game if and only if Robert is running. Michael is writing a letter if and only if it is sunny. Can we infer the following from them? If we can, name the inference rule being used: Michael is not writing a letter.
 From the fact that Linda is playing a game if and only if Robert is running, and that Robert is not running we can infer that Linda is not playing a game via biconditional elimination. From the fact that if William makes tea, then Linda is playing a game, and that Linda is not playing a game we can infer that William is not making tea via modus tollens. From the fact that if it is sunny, then William is making tea, and that William is not making tea we can infer that it is not sunny via modus tollens. Finally, from the fact that Michael is writing a letter if and only if it is sunny, and that it is not sunny we can infer that Michael is not writing a letter via biconditional elimination. Therefore, the answer is yes.