Consider the following premises. For all x_6, if x_6 were fast, then x_6 is an artist. For all x_6, x_6 is an artist if and only if x_6 is fast. Can we infer the following from them? If we can, name the inference rule being used: If James were fast, then James is an artist.
 From the fact that for all x_6, x_6 is an artist if and only if x_6 is fast we can infer that for all x_6, if x_6 were an artist, then x_6 is fast via universal biconditional elimination. From the fact that for all x_6, if x_6 were an artist, then x_6 is fast, and that for all x_6, if x_6 were fast, then x_6 is an artist we can infer that for all x_6, x_6 is an artist if and only if x_6 is fast via universal biconditional introduction. From the fact that for all x_6, x_6 is an artist if and only if x_6 is fast we can infer that James is an artist if and only if James is fast via universal instantiation. Finally, from the fact that James is an artist if and only if James is fast we can infer that if James were fast, then James is an artist via biconditional elimination. Therefore, the answer is yes.