Consider the following premises. It is cold if and only if Robert is playing a game. If it is cold, then Robert is playing a game. Robert is not playing a game. Karen is a sailor. Can we infer the following from them? If we can, name the inference rule being used: Karen is a sailor and it is not cold.
 From the fact that it is cold if and only if Robert is playing a game we can infer that if Robert plays a game, then it is cold via biconditional elimination. From the fact that if it is cold, then Robert is playing a game, and that if Robert plays a game, then it is cold we can infer that it is cold if and only if Robert is playing a game via biconditional introduction. From the fact that it is cold if and only if Robert is playing a game, and that Robert is not playing a game we can infer that it is not cold via biconditional elimination. Finally, from the fact that Karen is a sailor, and that it is not cold we can infer that Karen is a sailor and it is not cold via conjunction. Therefore, the answer is yes.