Consider the following premises. There is at least one x_6 for which x_6 is not a musician or x_6 will sleep. For all x_6, x_6 is a musician or x_6 will read a book. For all x_6, x_6 will take a plane if and only if x_6 will read a book. For all x_6, x_6 will not take a plane. Can we infer the following from them? There is at least one x_6 for which x_6 will sleep.
 From the fact that for all x_6, x_6 will take a plane if and only if x_6 will read a book, and that for all x_6, x_6 will not take a plane we can infer that for all x_6, x_6 will not read a book. From the fact that for all x_6, x_6 is a musician or x_6 will read a book, and that there is at least one x_6 for which x_6 is not a musician or x_6 will sleep we can infer that there is at least one x_6 for which x_6 will read a book or x_6 will sleep. Finally, from the fact that there is at least one x_6 for which x_6 will read a book or x_6 will sleep, and that for all x_6, x_6 will not read a book we can infer that there is at least one x_6 for which x_6 will sleep. Therefore, the answer is yes.