Consider the following premises. For all x_8, x_8 is an astronaut or x_8 is poor. For all x_8, if x_8 were a bartender, then x_8 is drinking water. For all x_8, x_8 is a bartender if and only if x_8 is poor. There is at least one x_8 for which if x_8 were an astronaut, then x_8 is drinking water. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_8 for which x_8 will drink water.
 From the fact that for all x_8, x_8 is a bartender if and only if x_8 is poor we can infer that for all x_8, if x_8 were poor, then x_8 is a bartender via universal biconditional elimination. From the fact that for all x_8, if x_8 were poor, then x_8 is a bartender, and that for all x_8, if x_8 were a bartender, then x_8 is drinking water we can infer that for all x_8, if x_8 were poor, then x_8 is drinking water via universal transitivity. Finally, from the fact that there is at least one x_8 for which if x_8 were an astronaut, then x_8 is drinking water, that for all x_8, if x_8 were poor, then x_8 is drinking water, and that for all x_8, x_8 is an astronaut or x_8 is poor we can infer that there is at least one x_8 for which x_8 will drink water via existential disjunction elimination. Therefore, the answer is yes.