Consider the following premises. There is at least one x_9 for which x_9 will not climb a mountain. For all x_9, if x_9 were a musician, then x_9 is climbing a mountain. For all x_9, if x_9 climbs a mountain, then x_9 is a musician. For all x_9, if x_9 were a writer, then x_9 is a musician. Can we infer the following from them? There is at least one x_9 for which x_9 is not a writer.
 From the fact that for all x_9, if x_9 were a musician, then x_9 is climbing a mountain, and that for all x_9, if x_9 climbs a mountain, then x_9 is a musician we can infer that for all x_9, x_9 is a musician if and only if x_9 will climb a mountain. From the fact that for all x_9, x_9 is a musician if and only if x_9 will climb a mountain, and that there is at least one x_9 for which x_9 will not climb a mountain we can infer that there is at least one x_9 for which x_9 is not a musician. Finally, from the fact that for all x_9, if x_9 were a writer, then x_9 is a musician, and that there is at least one x_9 for which x_9 is not a musician we can infer that there is at least one x_9 for which x_9 is not a writer. Therefore, the answer is yes.