Consider the following premises. For all z_3, if z_3 were a nurse, then z_3 is curious. For all z_3, z_3 is a nurse if and only if z_3 will sleep. For all z_3, if z_3 sleeps, then z_3 is a nurse. Can we infer the following from them? There is at least one z_3 for which the fact that z_3 sleeps does not imply that z_3 is curious.
 From the fact that for all z_3, z_3 is a nurse if and only if z_3 will sleep we can infer that for all z_3, if z_3 were a nurse, then z_3 is sleeping. From the fact that for all z_3, if z_3 sleeps, then z_3 is a nurse, and that for all z_3, if z_3 were a nurse, then z_3 is sleeping we can infer that for all z_3, z_3 will sleep if and only if z_3 is a nurse. From the fact that for all z_3, z_3 will sleep if and only if z_3 is a nurse we can infer that for all z_3, if z_3 sleeps, then z_3 is a nurse. Finally, from the fact that for all z_3, if z_3 sleeps, then z_3 is a nurse, and that for all z_3, if z_3 were a nurse, then z_3 is curious we can infer that for all z_3, if z_3 sleeps, then z_3 is curious, which contradicts that There is at least one z_3 for which the fact that z_3 sleeps does not imply that z_3 is curious. Therefore, the answer is no.