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Re: OWL DB, OWL UML, etc.

From: Bob MacGregor <macgregor@ISI.EDU>
Date: Thu, 13 May 2004 23:04:23 -0700
Message-Id: <>
To: Jim Hendler <hendler@cs.umd.edu>, www-rdf-logic@w3.org

I reread what you wrote a couple of more times, still find it a bit
confusing, but one phrase that puts me off track is
"how OWL extends the relational calculus".   Properly speaking,
I think you would have to say "how OWL extends a subset
of the relational calculus".   I'm wondering the following:
"Are you giving up some constructs (e.g., compound keys, and the
ability to count) while adding others, or are you imagining adding a
few more OWL constructs to what is already there (yielding a brand
new language strictly more expressive than the relational calculus)?

Cheers, Bob

At 03:26 PM 5/13/2004, Jim Hendler wrote:

>Umm, Bob, I guess I'm confused -- the idea I put forth is to figure out 
>how OWL extends the relational calculus --  Let's not confuse OWL's 
>ability to model what is in databases (as you discuss) with OWL's ability 
>to say things that are not expressible in the database schemas themselves 
>(as it is quite an expressive language and can say many things way beyond 
>the relation calculus) -- it's not that I disagree with what you say above 
>(I don't), it's just that I don't see how it relates to what I was asking...
>  -JH
>Professor James Hendler                   http://www.cs.umd.edu/users/hendler
>Director, Semantic Web and Agent Technologies     301-405-2696
>Maryland Information and Network Dynamics Lab.    301-405-6707 (Fax)
>Univ of Maryland, College Park, MD 20742          240-277-3388 (Cell)

Robert MacGregor
Senior Project Leader
Phone: 310/448-8423, Fax:  310/822-6592
Mobile: 310/251-8488

USC Information Sciences Institute
4676 Admiralty Way, Marina del Rey, CA 90292
Received on Friday, 14 May 2004 02:07:34 UTC

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