Consider the following premises. For all x_2, x_2 will work and x_2 is an astronaut. Can we infer the following from them? If we can, name the inference rule being used: Richard is not an astronaut.
 From the fact that for all x_2, x_2 will work and x_2 is an astronaut we can infer that Richard is working and Richard is an astronaut via universal instantiation. Finally, from the fact that Richard is working and Richard is an astronaut we can infer that Richard is working via simplification, which contradicts that Richard is not an astronaut. Therefore, the answer is no.