Consider the following premises. Sarah is not happy. It is snowing if and only if Sarah is happy. If it snows, then it is sunny. If it is sunny, then it is snowing. Can we infer the following from them? It is sunny.
 From the fact that it is snowing if and only if Sarah is happy, and that Sarah is not happy we can infer that it is not snowing. From the fact that if it snows, then it is sunny, and that if it is sunny, then it is snowing we can infer that it is snowing if and only if it is sunny. From the fact that it is snowing if and only if it is sunny we can infer that if it is sunny, then it is snowing. Finally, from the fact that if it is sunny, then it is snowing, and that it is not snowing we can infer that it is not sunny, which contradicts that It is sunny. Therefore, the answer is no.