Consider the following premises. For all x_7, if x_7 works, then x_7 is drinking water. For all x_7, if x_7 plays a game, then x_7 is working. For all x_7, x_7 is a soldier or x_7 will play a game. For all x_7, x_7 is a soldier if and only if x_7 will drink water. Can we infer the following from them? For all x_7, x_7 will drink water.
 From the fact that for all x_7, x_7 is a soldier if and only if x_7 will drink water we can infer that for all x_7, if x_7 were a soldier, then x_7 is drinking water. From the fact that for all x_7, if x_7 plays a game, then x_7 is working, and that for all x_7, if x_7 works, then x_7 is drinking water we can infer that for all x_7, if x_7 plays a game, then x_7 is drinking water. Finally, from the fact that for all x_7, if x_7 were a soldier, then x_7 is drinking water, that for all x_7, if x_7 plays a game, then x_7 is drinking water, and that for all x_7, x_7 is a soldier or x_7 will play a game we can infer that for all x_7, x_7 will drink water. Therefore, the answer is yes.