Consider the following premises. Jessica is a writer if and only if it is cold. For all y, y is not a writer. If Patricia were a musician, then it is cold. Can we infer the following from them? If we can, name the inference rule being used: Patricia is not a musician.
 From the fact that for all y, y is not a writer we can infer that Jessica is not a writer via universal instantiation. From the fact that Jessica is a writer if and only if it is cold, and that Jessica is not a writer we can infer that it is not cold via biconditional elimination. Finally, from the fact that if Patricia were a musician, then it is cold, and that it is not cold we can infer that Patricia is not a musician via modus tollens. Therefore, the answer is yes.