Consider the following premises. For all x_6, if x_6 were excited, then x_6 is an astronaut. For all x_6, x_6 will take a plane or x_6 will drink water. There is at least one x_6 for which x_6 is an astronaut if and only if x_6 will take a plane. For all x_6, if x_6 drinks water, then x_6 is excited. Can we infer the following from them? There is at least one x_6 for which x_6 is an astronaut.
 From the fact that for all x_6, if x_6 drinks water, then x_6 is excited, and that for all x_6, if x_6 were excited, then x_6 is an astronaut we can infer that for all x_6, if x_6 drinks water, then x_6 is an astronaut. From the fact that there is at least one x_6 for which x_6 is an astronaut if and only if x_6 will take a plane we can infer that there is at least one x_6 for which if x_6 takes a plane, then x_6 is an astronaut. Finally, from the fact that there is at least one x_6 for which if x_6 takes a plane, then x_6 is an astronaut, that for all x_6, if x_6 drinks water, then x_6 is an astronaut, and that for all x_6, x_6 will take a plane or x_6 will drink water we can infer that there is at least one x_6 for which x_6 is an astronaut. Therefore, the answer is yes.