Consider the following premises. For all x_8, x_8 will write a letter. For all x_8, x_8 will write a letter if and only if x_8 will play squash. Can we infer the following from them? There is at least one x for which x will play squash.
 From the fact that for all x_8, x_8 will write a letter if and only if x_8 will play squash we can infer that for all x_8, if x_8 writes a letter, then x_8 is playing squash. From the fact that for all x_8, if x_8 writes a letter, then x_8 is playing squash, and that for all x_8, x_8 will write a letter we can infer that for all x_8, x_8 will play squash. From the fact that for all x_8, x_8 will play squash we can infer that Jennifer is playing squash. Finally, from the fact that Jennifer is playing squash we can infer that there is at least one x for which x will play squash. Therefore, the answer is yes.