Consider the following premises. For all x_11, if x_11 takes a plane, then x_11 is a poet. For all x_11, if x_11 reads a book, then x_11 is taking a plane. For all x_11, x_11 will drink water or x_11 is not a poet. There is at least one x_11 for which if x_11 drinks water, then x_11 is reading a book. Can we infer the following from them? There is at least one x_11 for which x_11 will take a plane if and only if x_11 will read a book.
 From the fact that for all x_11, x_11 will drink water or x_11 is not a poet we can infer that for all x_11, if x_11 were a poet, then x_11 is drinking water. From the fact that for all x_11, if x_11 takes a plane, then x_11 is a poet, and that for all x_11, if x_11 were a poet, then x_11 is drinking water we can infer that for all x_11, if x_11 takes a plane, then x_11 is drinking water. From the fact that for all x_11, if x_11 takes a plane, then x_11 is drinking water, and that there is at least one x_11 for which if x_11 drinks water, then x_11 is reading a book we can infer that there is at least one x_11 for which if x_11 takes a plane, then x_11 is reading a book. Finally, from the fact that there is at least one x_11 for which if x_11 takes a plane, then x_11 is reading a book, and that for all x_11, if x_11 reads a book, then x_11 is taking a plane we can infer that there is at least one x_11 for which x_11 will take a plane if and only if x_11 will read a book. Therefore, the answer is yes.