Consider the following premises. For all x, x is a sailor if and only if x is an artist. If Richard were a sailor, then Joseph is a cashier. Joseph is not a cashier. Can we infer the following from them? If we can, name the inference rule being used: Richard is not an artist.
 From the fact that for all x, x is a sailor if and only if x is an artist we can infer that Richard is a sailor if and only if Richard is an artist via universal instantiation. From the fact that if Richard were a sailor, then Joseph is a cashier, and that Joseph is not a cashier we can infer that Richard is not a sailor via modus tollens. Finally, from the fact that Richard is a sailor if and only if Richard is an artist, and that Richard is not a sailor we can infer that Richard is not an artist via biconditional elimination. Therefore, the answer is yes.