Consider the following premises. Charles is not a police officer. Charles is a police officer if and only if Jennifer is a lawyer. Jennifer is a lawyer or it is snowing. Can we infer the following from them? If we can, name the inference rule being used: It is snowing.
 From the fact that Charles is a police officer if and only if Jennifer is a lawyer, and that Charles is not a police officer we can infer that Jennifer is not a lawyer via biconditional elimination. Finally, from the fact that Jennifer is a lawyer or it is snowing, and that Jennifer is not a lawyer we can infer that it is snowing via disjunctive syllogism. Therefore, the answer is yes.