Consider the following premises. For all x_15, if x_15 were a scientist, then x_15 is a writer. For all x_15, x_15 is a writer if and only if x_15 is rich. For all x_15, x_15 is an office clerk or x_15 is a police officer. For all x_15, x_15 is a scientist if and only if x_15 is an office clerk. For all x_15, if x_15 were a police officer, then x_15 is rich. Can we infer the following from them? There is at least one x_15 for which x_15 is not rich.
 From the fact that for all x_15, x_15 is a writer if and only if x_15 is rich we can infer that for all x_15, if x_15 were a writer, then x_15 is rich. From the fact that for all x_15, x_15 is a scientist if and only if x_15 is an office clerk we can infer that for all x_15, if x_15 were an office clerk, then x_15 is a scientist. From the fact that for all x_15, if x_15 were a scientist, then x_15 is a writer, and that for all x_15, if x_15 were a writer, then x_15 is rich we can infer that for all x_15, if x_15 were a scientist, then x_15 is rich. From the fact that for all x_15, if x_15 were an office clerk, then x_15 is a scientist, and that for all x_15, if x_15 were a scientist, then x_15 is rich we can infer that for all x_15, if x_15 were an office clerk, then x_15 is rich. Finally, from the fact that for all x_15, if x_15 were an office clerk, then x_15 is rich, that for all x_15, if x_15 were a police officer, then x_15 is rich, and that for all x_15, x_15 is an office clerk or x_15 is a police officer we can infer that for all x_15, x_15 is rich, which contradicts that There is at least one x_15 for which x_15 is not rich. Therefore, the answer is no.