W3C home > Mailing lists > Public > www-rdf-comments@w3.org > July to September 2002

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

From: pat hayes <phayes@ai.uwf.edu>
Date: Sun, 22 Sep 2002 16:32:25 -0500
Message-Id: <p05111b24b9b3e6fc1b89@[65.217.30.172]>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-rdf-comments@w3.org

>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


-- 
---------------------------------------------------------------------
IHMC					(850)434 8903   home
40 South Alcaniz St.			(850)202 4416   office
Pensacola,  FL 32501			(850)202 4440   fax
phayes@ai.uwf.edu 
http://www.coginst.uwf.edu/~phayes
Received on Sunday, 22 September 2002 17:32:30 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 21 September 2012 14:16:30 GMT