Class REGION

A region is the only entity which can be located at itself.
Subclass-Of: Localized-entity
Mapping: USN 'spatial-concept' can be mapped here.

Slots Of Instances:

Located:
Slot-Value-Type: Region
Axioms:
(Slot-Value-Type Region Part Region)

(=> (Region ?Self)
    (And (Exists (?A) (And (Proper-Part ?Self ?A) (Region ?A)))
         (Exists (?B) (And (Proper-Part-Of ?Self ?B) (Region ?B)))))