Consider the following premises. There is at least one y for which y will play tennis if and only if y is a soldier. For all y, if y were a soldier, then y is a scientist. For all y, y is a scientist if and only if y will play tennis. Can we infer the following from them? If we can, name the inference rule being used: For all y, the fact that y were a soldier does not imply that y is playing tennis.
That contradicts the premises. Therefore the answer is no.