Consider the following premises. For all x_6, if x_6 drinks water, then x_6 is sleeping. There is at least one x_6 for which x_6 will not sleep. For all x_6, x_6 will drink water if and only if x_6 is a carpenter. Can we infer the following from them? There is at least one x_6 for which x_6 is not a carpenter.
 From the fact that for all x_6, if x_6 drinks water, then x_6 is sleeping, and that there is at least one x_6 for which x_6 will not sleep we can infer that there is at least one x_6 for which x_6 will not drink water. From the fact that for all x_6, x_6 will drink water if and only if x_6 is a carpenter we can infer that for all x_6, if x_6 were a carpenter, then x_6 is drinking water. Finally, from the fact that for all x_6, if x_6 were a carpenter, then x_6 is drinking water, and that there is at least one x_6 for which x_6 will not drink water we can infer that there is at least one x_6 for which x_6 is not a carpenter. Therefore, the answer is yes.