Consider the following premises. There is at least one x_7 for which x_7 will make tea if and only if x_7 is a lawyer. For all x_7, x_7 is a police officer if and only if x_7 will write a letter. For all x_7, x_7 will write a letter if and only if x_7 will make tea. For all x_7, x_7 is not a police officer. Can we infer the following from them? For all x_7, x_7 is a lawyer.
 From the fact that for all x_7, x_7 is a police officer if and only if x_7 will write a letter, and that for all x_7, x_7 is not a police officer we can infer that for all x_7, x_7 will not write a letter. From the fact that for all x_7, x_7 will write a letter if and only if x_7 will make tea, and that for all x_7, x_7 will not write a letter we can infer that for all x_7, x_7 will not make tea. Finally, from the fact that there is at least one x_7 for which x_7 will make tea if and only if x_7 is a lawyer, and that for all x_7, x_7 will not make tea we can infer that there is at least one x_7 for which x_7 is not a lawyer, which contradicts that For all x_7, x_7 is a lawyer. Therefore, the answer is no.