Consider the following premises. For all x_6, x_6 will play squash. For all x_6, x_6 will write a letter or x_6 will not play squash. Can we infer the following from them? There is at least one x_6 for which neither x_6 will write a letter nor x_6 will listen to a song.
 From the fact that for all x_6, x_6 will write a letter or x_6 will not play squash we can infer that for all x_6, if x_6 plays squash, then x_6 is writing a letter. From the fact that for all x_6, if x_6 plays squash, then x_6 is writing a letter, and that for all x_6, x_6 will play squash we can infer that for all x_6, x_6 will write a letter. Finally, from the fact that for all x_6, x_6 will write a letter we can infer that for all x_6, x_6 will write a letter or x_6 will listen to a song, which contradicts that There is at least one x_6 for which neither x_6 will write a letter nor x_6 will listen to a song. Therefore, the answer is no.