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)

peter