Consider the following premises. For all x_1, if x_1 were a server, then x_1 is making tea. There is at least one x_1 for which x_1 will drive a car. For all x_1, x_1 is a server. Can we infer the following from them? If we can, name the inference rule being used: There is at least one x_1 for which x_1 will drive a car and x_1 will make tea.
 From the fact that for all x_1, if x_1 were a server, then x_1 is making tea, and that for all x_1, x_1 is a server we can infer that for all x_1, x_1 will make tea via universal modus ponens. Finally, from the fact that there is at least one x_1 for which x_1 will drive a car, and that for all x_1, x_1 will make tea we can infer that there is at least one x_1 for which x_1 will drive a car and x_1 will make tea via existential conjunction. Therefore, the answer is yes.