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