Consider the following premises. For all y_3, y_3 will make tea and y_3 will take a plane. Can we infer the following from them? There is at least one y_3 for which neither y_3 will make tea nor y_3 will sleep.
 From the fact that for all y_3, y_3 will make tea and y_3 will take a plane we can infer that for all y_3, y_3 will make tea. Finally, from the fact that for all y_3, y_3 will make tea we can infer that for all y_3, y_3 will make tea or y_3 will sleep, which contradicts that There is at least one y_3 for which neither y_3 will make tea nor y_3 will sleep. Therefore, the answer is no.