- From: Jos de Bruijn <jos.debruijn@deri.org>
- Date: Wed, 22 Jun 2005 17:59:33 +0200
- To: Jim Hendler <hendler@cs.umd.edu>
- CC: dreer@fh-furtwangen.de, public-sws-ig@w3.org
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Jim Hendler wrote:
> At 10:46 -0400 6/22/05, Jim Hendler wrote:
>
>> SWRL assumes closed world semantics and WRL assumes open world
>> semantics.
>
>
>
> oops, was typing quick and cutting and pasting and did this wrong ==
> should be clear that I meant exactly the opposite arragement - Sem
> Web is open world (cf SWRL) vs. the closed world semantics
> associated with datalog (cf WRL)
Actually Datalog is agnostic wrt. open/closed world.
As long as you don't have negation in the language there is no difference.
More precisely:
Any set of Horn rules R under First-Order semantics entails exactly
the same set of ground facts as the same set of rules R under minimal
model semantics.
Thus for any set of Horn rules R and any ground formula f_{ground}:
R \models_{FO} f_{ground} iff R \models_{MM} f_{ground}
where \models_{FO} is first-order entailment and \models_{MM} is
entailment under minimal model semantics
Best,
Jos
- --
Jos de Bruijn, http://www.uibk.ac.at/~c703239/
+43 512 507 6475 jos.debruijn@deri.org
DERI http://www.deri.org/
- ----------------------------------------------
Only two things are infinite, the universe and
human stupidity, and I'm not sure about the
former.
-- Albert Einstein
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Received on Wednesday, 22 June 2005 15:59:53 UTC