Consider the following premises. For all x_6, x_6 will take a plane or x_6 will play squash. For all x_6, if x_6 plays squash, then x_6 is a bartender. There is at least one x_6 for which x_6 will drink water if and only if x_6 is a bartender. For all x_6, x_6 will not take a plane or x_6 will drink water. Can we infer the following from them? There is at least one x_6 for which x_6 is a bartender.
 From the fact that there is at least one x_6 for which x_6 will drink water if and only if x_6 is a bartender we can infer that there is at least one x_6 for which if x_6 drinks water, then x_6 is a bartender. From the fact that for all x_6, x_6 will take a plane or x_6 will play squash, and that for all x_6, x_6 will not take a plane or x_6 will drink water we can infer that for all x_6, x_6 will play squash or x_6 will drink water. Finally, from the fact that for all x_6, if x_6 plays squash, then x_6 is a bartender, that there is at least one x_6 for which if x_6 drinks water, then x_6 is a bartender, and that for all x_6, x_6 will play squash or x_6 will drink water we can infer that there is at least one x_6 for which x_6 is a bartender. Therefore, the answer is yes.