Consider the following premises. For all x_9, x_9 will take a plane or x_9 is an office clerk. For all x_9, if x_9 takes a plane, then x_9 is a musician. For all x_9, if x_9 were a musician, then x_9 is taking a plane. For all x_9, x_9 is not a musician. Can we infer the following from them? There is at least one x_9 for which x_9 is not an office clerk.
 From the fact that for all x_9, if x_9 were a musician, then x_9 is taking a plane, and that for all x_9, if x_9 takes a plane, 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 take a plane. From the fact that for all x_9, x_9 is a musician if and only if x_9 will take a plane we can infer that for all x_9, if x_9 takes a plane, then x_9 is a musician. From the fact that for all x_9, if x_9 takes a plane, then x_9 is a musician, and that for all x_9, x_9 is not a musician we can infer that for all x_9, x_9 will not take a plane. Finally, from the fact that for all x_9, x_9 will take a plane or x_9 is an office clerk, and that for all x_9, x_9 will not take a plane we can infer that for all x_9, x_9 is an office clerk, which contradicts that There is at least one x_9 for which x_9 is not an office clerk. Therefore, the answer is no.