Consider the following premises. It is snowing or Thomas is not playing tennis. If it snows, then Thomas is playing tennis. Thomas is playing tennis. Can we infer the following from them? It is snowing.
 From the fact that it is snowing or Thomas is not playing tennis we can infer that if Thomas plays tennis, then it is snowing. From the fact that if Thomas plays tennis, then it is snowing, and that if it snows, then Thomas is playing tennis we can infer that Thomas is playing tennis if and only if it is snowing. From the fact that Thomas is playing tennis if and only if it is snowing we can infer that if Thomas plays tennis, then it is snowing. Finally, from the fact that if Thomas plays tennis, then it is snowing, and that Thomas is playing tennis we can infer that it is snowing. Therefore, the answer is yes.