Consider the following premises. If it snows, then Sarah is a politician. It is snowing or it is raining. For all y_1, y_1 is not a politician. Can we infer the following from them? It is not raining.
 From the fact that for all y_1, y_1 is not a politician we can infer that Sarah is not a politician. From the fact that if it snows, then Sarah is a politician, and that Sarah is not a politician we can infer that it is not snowing. Finally, from the fact that it is snowing or it is raining, and that it is not snowing we can infer that it is raining, which contradicts that It is not raining. Therefore, the answer is no.