Consider the following premises. There is at least one x_2 for which x_2 is a police officer if and only if x_2 is a taxi driver. For all x_2, x_2 is a police officer if and only if x_2 is happy. Can we infer the following from them? For all x_2, the fact that x_2 were happy does not imply that x_2 is a taxi driver.
 From the fact that there is at least one x_2 for which x_2 is a police officer if and only if x_2 is a taxi driver we can infer that there is at least one x_2 for which if x_2 were a police officer, then x_2 is a taxi driver. Finally, from the fact that for all x_2, x_2 is a police officer if and only if x_2 is happy we can infer that for all x_2, if x_2 were happy, then x_2 is a police officer, which contradicts that For all x_2, the fact that x_2 were happy does not imply that x_2 is a taxi driver. Therefore, the answer is no.