Consider the following premises. For all x_9, x_9 is a police officer if and only if x_9 is a mechanic. For all x_9, x_9 is a police officer if and only if x_9 is a lawyer. For all x_9, if x_9 were a police officer, then x_9 is a lawyer. For all x_9, x_9 is not a mechanic. Can we infer the following from them? There is at least one x_9 for which x_9 is a lawyer.
 From the fact that for all x_9, x_9 is a police officer if and only if x_9 is a lawyer we can infer that for all x_9, if x_9 were a lawyer, then x_9 is a police officer. From the fact that for all x_9, if x_9 were a police officer, then x_9 is a lawyer, and that for all x_9, if x_9 were a lawyer, then x_9 is a police officer we can infer that for all x_9, x_9 is a police officer if and only if x_9 is a lawyer. From the fact that for all x_9, x_9 is a police officer if and only if x_9 is a mechanic, and that for all x_9, x_9 is not a mechanic we can infer that for all x_9, x_9 is not a police officer. Finally, from the fact that for all x_9, x_9 is a police officer if and only if x_9 is a lawyer, and that for all x_9, x_9 is not a police officer we can infer that for all x_9, x_9 is not a lawyer, which contradicts that There is at least one x_9 for which x_9 is a lawyer. Therefore, the answer is no.