Notes for Product:
- Product is a special Role-Class.
- We could have defined this class as the superclass of
two sub-classes corresponding to the Product-for-Sale and
Product-Sold relatinshiops; however, this was not
deemed useful or necessary at this point.
Slots on class Product:
- Arity: 1
A Good-Service-or-Money that is either
1) offered For-Sale by a Vendor or 2) agreed to be
exchanged by the Vendor with the Actual-Customer
in a Sale.
- Instance-Of: Class, Relation, Set
- Subclass-Of: Qua-Entity, Eo-Entity, Individual, Individual-Thing, Thing ...
Slots on instances of Product:
Equivalence Axioms for Product:
(<=> (Product ?X)
(Or (Exists (?Sale) (Product-Sold ?Sale ?X))
(Exists (?For-Sale) (Product-For-Sale ?For-Sale ?X))))