Consider the following premises. For all x_7, x_7 will play squash if and only if x_7 will write a letter. For all x_7, x_7 will not play squash. For all x_7, x_7 will write a letter if and only if x_7 will make tea. There is at least one x_7 for which x_7 will make tea if and only if x_7 will read a book. Can we infer the following from them? There is at least one x_7 for which x_7 will not read a book.
 From the fact that for all x_7, x_7 will play squash if and only if x_7 will write a letter, and that for all x_7, x_7 will not play squash we can infer that for all x_7, x_7 will not write a letter. From the fact that for all x_7, x_7 will write a letter if and only if x_7 will make tea, and that for all x_7, x_7 will not write a letter we can infer that for all x_7, x_7 will not make tea. Finally, from the fact that there is at least one x_7 for which x_7 will make tea if and only if x_7 will read a book, and that for all x_7, x_7 will not make tea we can infer that there is at least one x_7 for which x_7 will not read a book. Therefore, the answer is yes.