Consider the following premises. If Robert were an electrician, then Joseph is driving a car. For all x_16, x_16 is an electrician if and only if x_16 is fast. Joseph is not driving a car. Can we infer the following from them? If we can, name the inference rule being used: Robert is fast.
 From the fact that for all x_16, x_16 is an electrician if and only if x_16 is fast we can infer that Robert is an electrician if and only if Robert is fast via universal instantiation. From the fact that if Robert were an electrician, then Joseph is driving a car, and that Joseph is not driving a car we can infer that Robert is not an electrician via modus tollens. Finally, from the fact that Robert is an electrician if and only if Robert is fast, and that Robert is not an electrician we can infer that Robert is not fast via biconditional elimination, which contradicts that Robert is fast. Therefore, the answer is no.