A happy household is one in which all members of the family dine together at least four nights out of the week. In order for a family to dine together on such a regular basis, one of two conditions must exist: The family members must not have busy schedules, or they must each be willing to make an effort to sacrifice time for one another. No one without a busy schedule is truly happy, since human beings must work in order to be happy. And a household may not be happy if any of its members is not happy.
Can someone please clarify the meaning of "may not" in the example above? I'm not sure if it means that the household is possibly not happy if any member is not happy, or if it means that the household can not be happy if any of its members is not happy.