Consider the following premises. Susan is not playing tennis. Susan is playing tennis if and only if it is snowing. Patricia is a janitor if and only if it is cold. It is snowing if and only if Patricia is a janitor. Can we infer the following from them? If we can, name the inference rule being used: It is not cold.
 From the fact that Susan is playing tennis if and only if it is snowing, and that Susan is not playing tennis we can infer that it is not snowing via biconditional elimination. From the fact that it is snowing if and only if Patricia is a janitor, and that it is not snowing we can infer that Patricia is not a janitor via biconditional elimination. Finally, from the fact that Patricia is a janitor if and only if it is cold, and that Patricia is not a janitor we can infer that it is not cold via biconditional elimination. Therefore, the answer is yes.