Re: bug in RDF model theory having to do with rdfs:subClassOf and rdfs:subPropertyOf

>The condition is
>
>if x subclassOf y then ICEXT(x) subset ICEXT(y)
>
>Suppose an RDF graph contains
>
>a subclass b .
>b subclass c .
>
>then an interpretation could have
>      <a,b> in IEXT(subClassOf)
>      <b,c> in IEXT(subClassOf)
>      ICEXT(a) = { u1 }
>      ICEXT(b) = { u1, u2 }
>      ICEXT(c) = { u1, u2, u3 }
>but nothing that I can see forces
>     <a,c> in IEXT(subClassof)

Yes, you are right. Defintely a bug; we will make the RDFS conditions 
IFF. Subclass (like class identity in OWL) ought to be determined by 
the class extensions. I still want to keep range and domain 
intensional, though.

Pat


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