Consider the following premises. For all x_3, if x_3 were poor, then x_3 is a janitor. For all x_3, x_3 is an astronaut if and only if x_3 is poor. Can we infer the following from them? There is at least one x_3 for which the fact that x_3 were an astronaut does not imply that x_3 is a janitor.
 From the fact that for all x_3, x_3 is an astronaut if and only if x_3 is poor we can infer that for all x_3, if x_3 were an astronaut, then x_3 is poor. Finally, from the fact that for all x_3, if x_3 were an astronaut, then x_3 is poor, and that for all x_3, if x_3 were poor, then x_3 is a janitor we can infer that for all x_3, if x_3 were an astronaut, then x_3 is a janitor, which contradicts that There is at least one x_3 for which the fact that x_3 were an astronaut does not imply that x_3 is a janitor. Therefore, the answer is no.