Consider the following premises. If Jennifer were a janitor, then it is sunny. If it is sunny, then it is snowing. It is cold. It is not snowing. Can we infer the following from them? If we can, name the inference rule being used: Jennifer is a janitor.
 From the fact that if Jennifer were a janitor, then it is sunny, and that if it is sunny, then it is snowing we can infer that if Jennifer were a janitor, then it is snowing via transitivity. Finally, from the fact that if Jennifer were a janitor, then it is snowing, and that it is not snowing we can infer that Jennifer is not a janitor via modus tollens, which contradicts that Jennifer is a janitor. Therefore, the answer is no.