Consider the following premises. There is at least one x_11 for which x_11 will drive a car or x_11 is a soldier. For all x_11, x_11 will play squash if and only if x_11 will sleep. For all x_11, x_11 will sleep or x_11 will not drive a car. For all x_11, x_11 will not play squash. Can we infer the following from them? There is at least one x_11 for which x_11 is a soldier.
 From the fact that for all x_11, x_11 will play squash if and only if x_11 will sleep, and that for all x_11, x_11 will not play squash we can infer that for all x_11, x_11 will not sleep. From the fact that for all x_11, x_11 will sleep or x_11 will not drive a car we can infer that for all x_11, if x_11 drives a car, then x_11 is sleeping. From the fact that for all x_11, if x_11 drives a car, then x_11 is sleeping, and that for all x_11, x_11 will not sleep we can infer that for all x_11, x_11 will not drive a car. Finally, from the fact that there is at least one x_11 for which x_11 will drive a car or x_11 is a soldier, and that for all x_11, x_11 will not drive a car we can infer that there is at least one x_11 for which x_11 is a soldier. Therefore, the answer is yes.