Relation ROLE-CARDINALITY

Given a concept and a relation, return the cardinality of the corresponding role.

Note that cardinality only exists if the min and max are the same.

Arity: 3
Range: Integer
Subrelation-Of: Role-max-cardinality, Role-min-cardinality
Axioms:
(Nth-Domain Role-Cardinality 2 Relation)

(Nth-Domain Role-Cardinality 1 Unary-Relation)

(<=> (Role-Cardinality ?A ?B ?C)
     (And (Role-Min-Cardinality ?A ?B ?C)
          (Role-Max-Cardinality ?A ?B ?C)))