Response to DM1

Hi David,

Thanks for your question.

David Mott wrote:
> 1) Please could you explain why condition 8 in section uses "superset of" 
> leading to the comment "a rdfs:subClassOf b is true if a ## b is true".
> Why is this not "equal to", leading to  "a rdfs:subClassOf b is true iff a ## b is true"?

RDFS semantics stipulates subclass to be reflexive, so for all a: a rdfs:subClassOf a. RIF subclass is not necessarily reflexive. You can assert that some class is a subclass of itself, but it isn't entailed for every class. Thus, every rif subclass relation is an rdfs one, but not the other way around.

> 2) for clarity, is the sentence "Since RIF frame formulas are interpreted using an extension function, as in RDF " in section 4 5th para, justified by the condition 4 in If so, could you add a pointer? 

No, those statements are justified by the RDF and RIF semantics. The "RDF&OWL" document just talks about combining them, and thus is just about combinations of RIF and RDF.

Please let us know if this is satisfactory.


Last modified on 25 August 2009, at 15:35