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Re: What does r:Bag mean?

From: Jimmy Cerra <jimbobbs@hotmail.com>
Date: Mon, 26 May 2003 00:53:37 -0400
To: <www-rdf-interest@w3.org>
Cc: <tpassin@comcast.net>
Message-ID: <000001c32342$c4f12ea0$1a6afea9@picard>

Tom,

Thanks for the reply; I really appreciate it.

> I do not think that you should model theCommittee as a bag.
> It would be better as the instance of some class (like
> Committee), with a property, say, Membership.  Membership
> would be a bag of members.  Now the committee can have a
> treasurer, who could be Jim, and that fact no longer has to
> get mixed up with the bag.  These questions have suddenly
> become moot - at least, they no longer arise for this example.

So a possible XML serialization would be:

<r:Description
  r:about="theCommitte"
  r:type="http://www.foo.com#Committee">
  <ex:treasurer rdf:resource="http://www.bar.com#Jim" />
  <ex:membership>
    <r:Bag>
      <r:li r:resource="http://www.bar.com#Jim" />
      <r:li r:resource="http://www.bar.com#John" />
      <r:li r:resource="http://www.bar.com#Jane" />
      <r:li r:resource="http://www.bar.com#Jamie" />
    </r:Bag>
  </ex:membership>
</r:Description>

Correct?  And the Bag represents an unordered set (in the mathematical
sense) of resource?  What would be the difference between that and the
following:

<r:Description
  r:about="theCommitte"
  r:type="http://www.foo.com#Committee">
  <ex:treasurer rdf:resource="http://www.bar.com#Jim" />
  <ex:membership r:resource="http://www.bar.com#Jim" />
  <ex:membership r:resource="http://www.bar.com#John" />
  <ex:membership r:resource="http://www.bar.com#Jane" />
  <ex:membership r:resource="http://www.bar.com#Jamie" />
</r:Description>

Does that mean the same thing?  How is the meaning different?  And how
is that different from:

<r:Description
  r:about="theCommitte"
  r:type="http://www.foo.com#Committee">
  <ex:treasurer rdf:resource="http://www.bar.com#Jim" />
  <ex:membership r:parseType="Collection">
      <r:type
        r:resource="http://www.w3.org/1999/02/22-rdf-syntax-ns#Bag" />
      <r:li r:resource="http://www.bar.com#Jim" />
      <r:li r:resource="http://www.bar.com#John" />
      <r:li r:resource="http://www.bar.com#Jane" />
      <r:li r:resource="http://www.bar.com#Jamie" />
  </ex:membership>
</r:Description>

I'm a bit confused about the semantics of each of the container
representations in RDF.

--
Jimmy Cerra

] "My mind is slipping away...
]  day by glorious day." - RAG III
Received on Monday, 26 May 2003 00:53:44 GMT

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