Consider the following premises. For all y, if y makes tea, then y is sad. For all y, if y plays tennis, then y is making tea. There is at least one y for which y will climb a mountain if and only if y is sad. For all y, y will climb a mountain or y will play tennis. Can we infer the following from them? There is at least one y for which y is sad.
 From the fact that for all y, if y plays tennis, then y is making tea, and that for all y, if y makes tea, then y is sad we can infer that for all y, if y plays tennis, then y is sad. From the fact that there is at least one y for which y will climb a mountain if and only if y is sad we can infer that there is at least one y for which if y climbs a mountain, then y is sad. Finally, from the fact that there is at least one y for which if y climbs a mountain, then y is sad, that for all y, if y plays tennis, then y is sad, and that for all y, y will climb a mountain or y will play tennis we can infer that there is at least one y for which y is sad. Therefore, the answer is yes.