Consider the following premises. For all x_5, if x_5 climbs a mountain, then x_5 is taking a plane. For all x_5, if x_5 goes running, then x_5 is climbing a mountain. For all x_5, if x_5 were a mechanic, then x_5 is running. For all x_5, if x_5 were an astronaut, then x_5 is a mechanic. Can we infer the following from them? For all x_5, if x_5 were an astronaut, then x_5 is taking a plane.
 From the fact that for all x_5, if x_5 were an astronaut, then x_5 is a mechanic, and that for all x_5, if x_5 were a mechanic, then x_5 is running we can infer that for all x_5, if x_5 were an astronaut, then x_5 is running. From the fact that for all x_5, if x_5 were an astronaut, then x_5 is running, and that for all x_5, if x_5 goes running, then x_5 is climbing a mountain we can infer that for all x_5, if x_5 were an astronaut, then x_5 is climbing a mountain. Finally, from the fact that for all x_5, if x_5 were an astronaut, then x_5 is climbing a mountain, and that for all x_5, if x_5 climbs a mountain, then x_5 is taking a plane we can infer that for all x_5, if x_5 were an astronaut, then x_5 is taking a plane. Therefore, the answer is yes.