Consider the following premises. James is not happy. For all x_11, x_11 is happy if and only if x_11 is a writer. If Richard were a musician, then James is a writer. Can we infer the following from them? Richard is not a musician.
 From the fact that for all x_11, x_11 is happy if and only if x_11 is a writer we can infer that James is happy if and only if James is a writer. From the fact that James is happy if and only if James is a writer, and that James is not happy we can infer that James is not a writer. Finally, from the fact that if Richard were a musician, then James is a writer, and that James is not a writer we can infer that Richard is not a musician. Therefore, the answer is yes.