owl:equivalentClass and rds:subClassOf

Follow-up of a debate in Protégé list.

Holger Knublauch wrote:

"... in Protege there is no way to distinguish between

 :A rdfs:subClassOf :B
 :B rdfs:subClassOf :A

and

 :A owl:equivalentClass :B

because they are internally mapped into mutual superclasses..."

The reciprocal rdfs:subClassOf declares a logical equivalence of definition
(intensional), whereas owl:equivalentClass declares an equivalence at
instance level (extensional).

Should those declarations be kept distinct or not by a conformant OWL tool?
And if yes, what would be the logical relationship, if any, between the
former and the latter?

Bernard Vatant
Senior Consultant
Knowledge Engineering
Mondeca - www.mondeca.com
bernard.vatant@mondeca.com