Consider the following premises. For all x_7, x_7 will listen to a song. For all x_7, if x_7 were sad, then x_7 is not listening to a song. There is at least one x_7 for which x_7 is sad or x_7 will not play tennis. Can we infer the following from them? For all x_7, x_7 will play tennis.
 From the fact that for all x_7, if x_7 were sad, then x_7 is not listening to a song, and that for all x_7, x_7 will listen to a song we can infer that for all x_7, x_7 is not sad. From the fact that there is at least one x_7 for which x_7 is sad or x_7 will not play tennis we can infer that there is at least one x_7 for which if x_7 plays tennis, then x_7 is sad. Finally, from the fact that there is at least one x_7 for which if x_7 plays tennis, then x_7 is sad, and that for all x_7, x_7 is not sad we can infer that there is at least one x_7 for which x_7 will not play tennis, which contradicts that For all x_7, x_7 will play tennis. Therefore, the answer is no.