In a disjointness design constraint,
an entity can belong to not more than one lower-level entity set.
In overlapping generalizations, the same entity may belong to more than one lower-level entity sets.
For example, in the employee-workteam example of the book, a manager may participate in more than one work-team.
an entity can belong to not more than one lower-level entity set.
In overlapping generalizations, the same entity may belong to more than one lower-level entity sets.
For example, in the employee-workteam example of the book, a manager may participate in more than one work-team.