Consider the following premises. For all x_9, x_9 is a poet if and only if x_9 will sleep. For all x_9, x_9 will not sleep. There is at least one x_9 for which x_9 is a poet if and only if x_9 will drink water. Can we infer the following from them? For all x_9, x_9 will drink water.
 From the fact that there is at least one x_9 for which x_9 is a poet if and only if x_9 will drink water we can infer that there is at least one x_9 for which if x_9 drinks water, then x_9 is a poet. From the fact that for all x_9, x_9 is a poet if and only if x_9 will sleep, and that for all x_9, x_9 will not sleep we can infer that for all x_9, x_9 is not a poet. Finally, from the fact that there is at least one x_9 for which if x_9 drinks water, then x_9 is a poet, and that for all x_9, x_9 is not a poet we can infer that there is at least one x_9 for which x_9 will not drink water, which contradicts that For all x_9, x_9 will drink water. Therefore, the answer is no.