Consider the following premises. If it is cold, then it is sunny. Susan is a taxi driver or it is cold. It is not sunny. If it is sunny, then it is cold. Can we infer the following from them? If we can, name the inference rule being used: Susan is not a taxi driver.
 From the fact that if it is sunny, then it is cold, and that if it is cold, then it is sunny we can infer that it is sunny if and only if it is cold via biconditional introduction. From the fact that it is sunny if and only if it is cold, and that it is not sunny we can infer that it is not cold via biconditional elimination. From the fact that Susan is a taxi driver or it is cold we can infer that if it is not cold, then Susan is a taxi driver via rewriting. Finally, from the fact that if it is not cold, then Susan is a taxi driver, and that it is not cold we can infer that Susan is a taxi driver via modus ponens, which contradicts that Susan is not a taxi driver. Therefore, the answer is no.