Consider the following premises. For all x_10, x_10 is not a musician. For all x_10, x_10 will work or x_10 is fast. There is at least one x_10 for which x_10 is fast if and only if x_10 is a musician. For all x_10, x_10 will not work or x_10 is a doctor. Can we infer the following from them? There is at least one x_10 for which x_10 is a doctor.
 From the fact that for all x_10, x_10 will work or x_10 is fast, and that for all x_10, x_10 will not work or x_10 is a doctor we can infer that for all x_10, x_10 is fast or x_10 is a doctor. From the fact that there is at least one x_10 for which x_10 is fast if and only if x_10 is a musician, and that for all x_10, x_10 is not a musician we can infer that there is at least one x_10 for which x_10 is not fast. Finally, from the fact that for all x_10, x_10 is fast or x_10 is a doctor, and that there is at least one x_10 for which x_10 is not fast we can infer that there is at least one x_10 for which x_10 is a doctor. Therefore, the answer is yes.