Consider the following premises. If Jennifer were happy, then Jennifer is a writer. It is snowing if and only if Jennifer is a writer. It is snowing or Jennifer is happy. Can we infer the following from them? If we can, name the inference rule being used: Jennifer is a writer or Sarah is sleeping.
 From the fact that it is snowing if and only if Jennifer is a writer we can infer that if it snows, then Jennifer is a writer via biconditional elimination. From the fact that if it snows, then Jennifer is a writer, that if Jennifer were happy, then Jennifer is a writer, and that it is snowing or Jennifer is happy we can infer that Jennifer is a writer via disjunction elimination. Finally, from the fact that Jennifer is a writer we can infer that Jennifer is a writer or Sarah is sleeping via addition. Therefore, the answer is yes.