It is possible to propagate notification to a parent type just as it is propagated to a relation. To examplify this point, let’s assume —though it is not very realistic— that a manager object has a n-ary relation managed whose targets are the set of employees it manages.

Let us also assume a view on the manager represents each employee as a row in a table associated with the manager:

This specification works unless some other manager objects appear in the managed relation. In that case, those “managed Managers” will be represented by a table and not by a row. This is not the expected result!

To overcome this potential problem, all you have to do is to modify the specification as follows:

Now, the notification to a Manager object depends on whether this object is the view origin or not. If not, the notification is propagated to the parent class Employee, so that the Manager object itself is represented as a row.