Consider the following premises. For all z, z will not drink water. For all z, if z drives a car, then z is drinking water. There is at least one z for which if z drinks water, then z is driving a car. Can we infer the following from them? If we can, name the inference rule being used: For all z, z will drive a car.
 From the fact that there is at least one z for which if z drinks water, then z is driving a car, and that for all z, if z drives a car, then z is drinking water we can infer that there is at least one z for which z will drink water if and only if z will drive a car via existential biconditional introduction. Finally, from the fact that there is at least one z for which z will drink water if and only if z will drive a car, and that for all z, z will not drink water we can infer that there is at least one z for which z will not drive a car via existential biconditional elimination, which contradicts that For all z, z will drive a car. Therefore, the answer is no.