Consider the following premises. For all x_7, x_7 is a nurse if and only if x_7 is a server. Richard is not driving a car. Michael is a nurse if and only if Richard is driving a car. Can we infer the following from them? If we can, name the inference rule being used: Michael is a server.
 From the fact that for all x_7, x_7 is a nurse if and only if x_7 is a server we can infer that Michael is a nurse if and only if Michael is a server via universal instantiation. From the fact that Michael is a nurse if and only if Richard is driving a car, and that Richard is not driving a car we can infer that Michael is not a nurse via biconditional elimination. Finally, from the fact that Michael is a nurse if and only if Michael is a server, and that Michael is not a nurse we can infer that Michael is not a server via biconditional elimination, which contradicts that Michael is a server. Therefore, the answer is no.