Consider the following premises. For all x_12, if x_12 were a taxi driver, then x_12 is a nurse. For all x_12, x_12 is a taxi driver if and only if x_12 will drink water. For all x_12, x_12 is a taxi driver if and only if x_12 is a nurse. Can we infer the following from them? For all x_12, if x_12 were a nurse, then x_12 is drinking water.
 From the fact that for all x_12, x_12 is a taxi driver if and only if x_12 will drink water we can infer that for all x_12, if x_12 were a taxi driver, then x_12 is drinking water. From the fact that for all x_12, x_12 is a taxi driver if and only if x_12 is a nurse we can infer that for all x_12, if x_12 were a nurse, then x_12 is a taxi driver. From the fact that for all x_12, if x_12 were a taxi driver, then x_12 is a nurse, and that for all x_12, if x_12 were a nurse, then x_12 is a taxi driver we can infer that for all x_12, x_12 is a taxi driver if and only if x_12 is a nurse. From the fact that for all x_12, x_12 is a taxi driver if and only if x_12 is a nurse we can infer that for all x_12, if x_12 were a nurse, then x_12 is a taxi driver. Finally, from the fact that for all x_12, if x_12 were a nurse, then x_12 is a taxi driver, and that for all x_12, if x_12 were a taxi driver, then x_12 is drinking water we can infer that for all x_12, if x_12 were a nurse, then x_12 is drinking water. Therefore, the answer is yes.