Consider the following premises. For all z_4, if z_4 drives a car, then z_4 is taking a plane. For all z_4, z_4 will climb a mountain if and only if z_4 will take a plane. For all z_4, z_4 is an astronaut or z_4 will climb a mountain. There is at least one z_4 for which z_4 is not an astronaut or z_4 will drive a car. Can we infer the following from them? If we can, name the inference rule being used: There is at least one z_4 for which z_4 will take a plane.
 From the fact that for all z_4, z_4 will climb a mountain if and only if z_4 will take a plane we can infer that for all z_4, if z_4 climbs a mountain, then z_4 is taking a plane via universal biconditional elimination. From the fact that for all z_4, z_4 is an astronaut or z_4 will climb a mountain, and that there is at least one z_4 for which z_4 is not an astronaut or z_4 will drive a car we can infer that there is at least one z_4 for which z_4 will climb a mountain or z_4 will drive a car via existential resolution. Finally, from the fact that for all z_4, if z_4 climbs a mountain, then z_4 is taking a plane, that for all z_4, if z_4 drives a car, then z_4 is taking a plane, and that there is at least one z_4 for which z_4 will climb a mountain or z_4 will drive a car we can infer that there is at least one z_4 for which z_4 will take a plane via existential disjunction elimination. Therefore, the answer is yes.