Consider the following premises. There is at least one z for which if z were happy, then z is driving a car. For all z, if z drives a car, then z is happy. For all z, z will not drive a car. For all z, if z drives a car, then z is happy. Can we infer the following from them? For all z, z is happy.
 From the fact that there is at least one z for which if z were happy, then z is driving a car, and that for all z, if z drives a car, then z is happy we can infer that there is at least one z for which z is happy if and only if z will drive a car. From the fact that there is at least one z for which z is happy if and only if z will drive a car we can infer that there is at least one z for which if z were happy, then z is driving a car. From the fact that there is at least one z for which if z were happy, then z is driving a car, and that for all z, if z drives a car, then z is happy we can infer that there is at least one z for which z is happy if and only if z will drive a car. Finally, from the fact that there is at least one z for which z is happy if and only if z will drive a car, and that for all z, z will not drive a car we can infer that there is at least one z for which z is not happy, which contradicts that For all z, z is happy. Therefore, the answer is no.