Consider the following premises. For all x_6, if x_6 plays a game, then x_6 is sad. There is at least one x_6 for which x_6 will play a game if and only if x_6 will drive a car. For all x_6, x_6 is not sad. Can we infer the following from them? For all x_6, x_6 will drive a car.
 From the fact that for all x_6, if x_6 plays a game, then x_6 is sad, and that for all x_6, x_6 is not sad we can infer that for all x_6, x_6 will not play a game. From the fact that there is at least one x_6 for which x_6 will play a game if and only if x_6 will drive a car we can infer that there is at least one x_6 for which if x_6 drives a car, then x_6 is playing a game. Finally, from the fact that there is at least one x_6 for which if x_6 drives a car, then x_6 is playing a game, and that for all x_6, x_6 will not play a game we can infer that there is at least one x_6 for which x_6 will not drive a car, which contradicts that For all x_6, x_6 will drive a car. Therefore, the answer is no.