Consider the following premises. For all x_1, if x_1 drinks water, then x_1 is writing a letter. For all x_1, if x_1 plays squash, then x_1 is writing a letter. For all x_1, x_1 is a soldier or x_1 will play squash. For all x_1, if x_1 were a soldier, then x_1 is drinking water. Can we infer the following from them? For all x_1, x_1 will write a letter.
 From the fact that for all x_1, if x_1 were a soldier, then x_1 is drinking water, and that for all x_1, if x_1 drinks water, then x_1 is writing a letter we can infer that for all x_1, if x_1 were a soldier, then x_1 is writing a letter. Finally, from the fact that for all x_1, if x_1 were a soldier, then x_1 is writing a letter, that for all x_1, if x_1 plays squash, then x_1 is writing a letter, and that for all x_1, x_1 is a soldier or x_1 will play squash we can infer that for all x_1, x_1 will write a letter. Therefore, the answer is yes.