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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 11:14:04 -0500
Message-ID: <B8E84F4D9F65D411803500508BE3221410841B25@USPLM207>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: www-webont-wg@w3.org

Peter,

>> Define owl:ontology to be an extended alias for rdf:rdf.  An OWL
>> ontology would then look like
>> 
>> <owl:ontology about=""
>>               xmlns="#" 
>>               xmlns:rdf=...>
>>  <owl:imports about="" rdf:resource="uri1">
>>  ...
>> </owl:ontology>
>
> [snip] However, then the imports stuff is a node element, and
> not a property element.

Good point.  So let each import be an instance of the import class,
with an imports relation to the uri.  

<owl:ontology about="" ... >
 <owl:import imports="uri1"/>
 <owl:import imports="uri2"/>
 ..
</rdf:RDF>

If the primary utility of this statement is to pull in another
ontology, we really don't care too much what this looks like in RDF,
as long as it isn't complete nonsense and doesn't generate any bogus
entailments.  We want OWL to effectively discard it.  It should work
like a comment.  It is astonishing that it is so hard to define such a
thing.  Don't get me started.

- Mike

-----Original Message-----
From: Peter F. Patel-Schneider [mailto:pfps@research.bell-labs.com]
Sent: Tuesday, September 17, 2002 10:29 AM
To: Smith, Michael K
Cc: www-webont-wg@w3.org
Subject: Re: LANG: syntactic version for imports (and other things)


From: "Smith, Michael K" <michael.smith@eds.com>
Subject: RE: LANG: syntactic version for imports (and other things)
Date: Tue, 17 Sep 2002 10:08:12 -0500

> 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),
> 
> 2. provide a strictly syntactic explanation for imports (at least I
> would like to see this), and
> 
> 3. maintain the basic RDF striping XML syntax.
> 
> Note that RDF tools are going to need to make some slight changes
> already (for example to support parsetype collection).
> 
> SUGGESTION
> 
> Define owl:ontology to be an extended alias for rdf:rdf.  An OWL
> ontology would then look like
> 
> <owl:ontology about=""
>               xmlns="#" 
>               xmlns:rdf=...>
>  <owl:imports about="" rdf:resource="uri1">
>  ...
> </owl:ontology>

Good idea, particularly having OWL documents be RDF documents (or whatever
the the top-level of RDF is called) but owl:ontology elements instead of
rdf:RDF elements.  However, then the imports stuff is a node element, and
not a property element.

> The 'about' attribute (ignored by RDF) defines a name for the
> ontology.  The standard cliche defaults to the document URL, 
> but we could insert an explicit URI if desired.
> I believe that well engineered ontologies will want to be associated
> with a URN so that they are not tied to a physical location.

> I'm still not clear on whether we want to introduce an ontology
> resource into the RDF triple world.  We could always leave off the
> 'about=""' in the imports clause and get an existential triple like
> 
> _g001 owl:imports uri1

A node element doesn't work this way.

> In either case, the expansion of the imports could then be made to
> work in a natural way, but would require supporting multiple
> owl:ontology expressions in one file.  E.g.

Expansion of imports doesn't have to result in a ``file''.  It can be
handled in a special way in the syntax.

> <owl:ontology about=""
>               xmlns="#" 
>               xmlns:rdf=...>
>  ...
> </owl:ontology>
> 
> <owl:ontology xml:Base="uri1"
>               xmlns:ns11="uri11" ...
>               xmlns:ns1i="uri1i" 
>               about=""> 
>  ... 
> </owl:ontology>
> 
> - Mike
Received on Tuesday, 17 September 2002 12:14:15 GMT

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