Superclass-of is the inverse of the subclass-of relation. It is useful to create an explicit inverse because there are efficient ways to assert and query superclass and subclass relationships separately.In Cyc, superclass-of is called #%allSpecs because it is a slot from a collection to all of its specializations (subclasses).
Notes:
- We could have named superclass-of something like `has-subclasses' or `subclasses'. These look better when displayed as slots on frames. We opted for `superclass-of' because it is less ambiguous. Frame editors and related tools are free to alias this relation.