如何在使用Core Data时正确设置NSPredicate以实现多对多关系？

I have a Core Data model in which a Task entity includes an optional to-many relationship ExcludedDays to the ExcludedDay entity. One of the properties of ExcludedDay is day, which is an NSDate object. The ExcludedDay entity has an inverse mandatory to-one relationship to the Task entity.I have a Core Data model in which a Task entity