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Re: DAML-S 0.6: use of classes vs instances

From: David Martin <martin@ai.sri.com>
Date: Tue, 27 Nov 2001 07:08:15 -0800
Message-ID: <3C03AC5F.E2884677@ai.sri.com>
To: "Dickinson, Ian J" <Ian_Dickinson@hp.com>
CC: "'www-ws@w3c.org'" <www-ws@w3c.org>
Ian -

Thanks for your interest and excellent questions about DAML-S.  I don't
have time at this moment to address your questions, but I or another
member of the DAML-S team will do so shortly.

However, I'd like to hasten to point out that the URL you're looking at
does *NOT* contain a release of DAML-S, but rather contains working
drafts of V 0.6 material that will be released on December 5 (and these
are not necessarily the latest drafts)!

The 0.6 version will be made available here, on December 5:

    http://www.daml.org/services/

(and 0.5 is, of course, already available there).

Regards,

-- David Martin

"Dickinson, Ian J" wrote:
> 
> Folks -
> A Jena user asked a question about Jena support for DAML-S, and pointed me
> at the latest version of the specs on
> http://www.daml.ri.cmu.edu/ont/DAML-S/Release0.6/. Since I wasn't familiar
> with the details of DAML-S, I've spent a little time trying to get up to
> speed.  I'm sure I'll have a number of questions, but one leaps right out at
> me from reading the Congo and Bravo Air examples.
> 
> In essence it is this: where's the data?
> 
> To be more precise, I notice that all of the definitions are for DAML
> classes and properties. Nowhere are instances defined, or actual RDF triples
> giving the properties of the instances. So when congo.daml says:
> 
> <daml:Class rdf:ID="CongoBuy">
>   <rdfs:subClassOf rdf:resource="&process;#AtomicProcess"/>
> </daml:Class>
> 
> this tells me that there is a DAML class CongoBuy, all instances of which
> are also instances of AtomicProcesses, but it doesn't tell me that there is
> an individual CongoBuy service that I can interact with.  Similarly:
> 
> <rdf:Property rdf:ID="congoBuyCreditExistsPrecondition">
>   <rdfs:subPropertyOf rdf:resource="&process;#precondition"/>
>   <rdfs:domain rdf:resource="#CongoBuy"/>
>   <rdfs:range rdf:resource="#CreditExists"/>
> </rdf:Property>
> 
> says that there can be statements relating instances that are CongoBuy's to
> instances that are CreditExists, and that the set of pairs that define
> 'congoBuyCreditExistsPrecondition' is a subset of the set of pairs that
> define 'precondition', but not that a given CongoBuy service has the
> precondition that CreditExists.
> 
> I could use all this information to *validate* any RDF data I could find
> that described one or more CongoBuy services, but I don't see how I could
> find Congo and actually buy a book without some instance data.
> 
> Equally plausibly, I've completely missed the point :-)   All comments
> welcome.
> 
> Thanks,
> Ian
Received on Tuesday, 27 November 2001 10:07:25 GMT

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