Consider the following premises. For all x_4, x_4 will not read a book. There is at least one x_4 for which x_4 will read a book or x_4 will drive a car. Can we infer the following from them? There is at least one x_4 for which x_4 will drive a car or x_4 will write a letter.
 From the fact that there is at least one x_4 for which x_4 will read a book or x_4 will drive a car, and that for all x_4, x_4 will not read a book we can infer that there is at least one x_4 for which x_4 will drive a car. Finally, from the fact that there is at least one x_4 for which x_4 will drive a car we can infer that there is at least one x_4 for which x_4 will drive a car or x_4 will write a letter. Therefore, the answer is yes.