intersect relation

An intersect relation between a subset and a number of super sets defines the subset as the intersection of all its super sets, i.e. the super set can be considered as derived from its subsets. Adding an instance to the super set will add this instance to all subsets.

Intersect relations for controlled extents are maintained automatically, which means, that one cannot remove instances from an intersect extent. Instances have to be removed from appropriate base extents, instead.