R170 - modelint/shlaer-mellor-metamodel GitHub Wiki

R170 / 1:M

Generalization Reference refers to exactly one Superclass

Superclass is referred to by one or many Generalization Reference

---

By definition, a Generalization Reference refers to the Generalization Relationship's Superclass. Since every Generalization requires at least two Subclasses, the Superclass must be referenced at least twice in any Generalization.

Formalization

Generalization Reference.(Superclass, Rnum, Domain) -> Superclass.(Name, Rnum, Domain)