Consider the following premises. Jennifer is an artist or it is not late. Jennifer is an artist if and only if Patricia is writing a letter. If Patricia writes a letter, then it is late. Can we infer the following from them? If we can, name the inference rule being used: If Jennifer were an artist, then Patricia is writing a letter.
 From the fact that Jennifer is an artist or it is not late we can infer that if it is late, then Jennifer is an artist via rewriting. From the fact that if Patricia writes a letter, then it is late, and that if it is late, then Jennifer is an artist we can infer that if Patricia writes a letter, then Jennifer is an artist via transitivity. Finally, from the fact that Jennifer is an artist if and only if Patricia is writing a letter we can infer that if Jennifer were an artist, then Patricia is writing a letter via biconditional elimination. Therefore, the answer is yes.