Consider the following premises. If it is cold, then Thomas is not a writer. Thomas is a writer. Jennifer is a lawyer if and only if Karen is a politician. Jennifer is a lawyer if and only if it is cold. Can we infer the following from them? If we can, name the inference rule being used: Karen is a politician.
 From the fact that if it is cold, then Thomas is not a writer, and that Thomas is a writer we can infer that it is not cold via modus tollens. From the fact that Jennifer is a lawyer if and only if Karen is a politician we can infer that if Karen were a politician, then Jennifer is a lawyer via biconditional elimination. From the fact that Jennifer is a lawyer if and only if it is cold, and that it is not cold we can infer that Jennifer is not a lawyer via biconditional elimination. Finally, from the fact that if Karen were a politician, then Jennifer is a lawyer, and that Jennifer is not a lawyer we can infer that Karen is not a politician via modus tollens, which contradicts that Karen is a politician. Therefore, the answer is no.