Relation ALIAS

Alias is a way to specify that two relations have the same extension. It is logically equivalent to the = relation, except that it is restricted to relations.
Arity: 2
Domain: Relation
Range: Relation
Subrelation-Of: =
Axioms:
(<=> (Alias ?Relation-1 ?Relation-2)
     (And (Relation ?Relation-1)
          (Relation ?Relation-2)
          (= ?Relation-1 ?Relation-2)))