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RE: LANG: syntactic version for imports (and other things)

From: Smith, Michael K <michael.smith@eds.com>
Date: Tue, 17 Sep 2002 18:42:27 -0500
Message-ID: <B8E84F4D9F65D411803500508BE32214108B4784@USPLM207>
To: pat hayes <phayes@ai.uwf.edu>
Cc: www-webont-wg@w3.org

One reason I would like to see a simple, syntactic account it that it
provides a lowest common denominator.  Even in the world of XML, I think of
syntax as simpler than semantics.  An implementor is free to be smarter if
he wants, but anyone building OWL tools should at least be capable of simple
syntactic transformations.

I was trying to avoid giving a semantic account to something that has been
introduced as extra-logical.  And appealing to the entailments provided by
the merge of RDF graphs, when the OWL semantics is phrased in terms of the
abstract syntax, just seems harder.

- Mike

-----Original Message-----
From: pat hayes [mailto:phayes@ai.uwf.edu]
Sent: Tuesday, September 17, 2002 6:26 PM
To: Smith, Michael K
Cc: www-webont-wg@w3.org
Subject: RE: LANG: syntactic version for imports (and other things)


>Well now that I have slept on my flame I have a concrete suggestion.
>
>MOTIVIATION
>
>There is a desire to
>
>1. indicate that a set of class, property, and individual definitions
>are part of an ontology using a natural scoping mechanism (even if
>this is an extra-logical relationship),

In order to make sense of this we have to say what counts as an 
ontology and what counts as a 'part'. I suggest that much of the 
confusion arises from different assumptions being made about what 
these answers are/should be. I would also suggest that we agree that 
since OWL is an extension of RDF, that the appropriate answer would 
be that an ontology is an RDF graph (set of RDF triples) and that 
'part' means 'subset'. Not all RDF graphs are OWL ontologies, but all 
OWL ontologies are RDF graphs. Note, this is not the same as assuming 
that 'part' means anything meaningful about XML sub-expressions, and 
I suggest that there is no need why it should.

>
>2. provide a strictly syntactic explanation for imports (at least I
>would like to see this),

I would like to NOT have 'imports' defined this way. I think this 
would be a disaster, and would make imports effectively unusable by a 
fair proportion (say half) of the potential users. One could however 
observe that the entailments notion of imports (see my previous 
message to Peter) can be reliably achieved by a syntactic merge of 
the RDF graphs, which is a kind of syntactic account.

Pat
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Received on Tuesday, 17 September 2002 19:42:36 GMT

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