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RE: RDF's binary nature

From: Tom Reilly <treilly@macromedia.com>
Date: Thu, 19 Jun 2003 13:19:11 -0400
Message-ID: <CB1FF0A474AEA84EA0206D5B05F6A4CB0210DA93@S1001EXM02.macromedia.com>
To: "'danny666@virgilio.it'" <danny666@virgilio.it>, www-rdf-interest@w3.org


I realize that, by "binary" I was referring to this:

http://www.w3.org/TR/1999/REC-rdf-syntax-19990222/#ex-NonBinary

This may in fact be a good place to point out that just because 
statements are binary doesn't mean that a resource can't have 
more than one statement about it with the same predicate.

+1 on making this clearer in the RDF Primer and anywhere else it might
make sense.  Might help newbies from making the same incorrect
assumption I did.

Thanks,
Tom

> -----Original Message-----
> From: Danny Ayers [mailto:danny666@virgilio.it] 
> Sent: Thursday, June 19, 2003 1:04 PM
> To: Tom Reilly; www-rdf-interest@w3.org
> Subject: RE: RDF's binary nature
> 
> 
> Hi Tom,
> 
> RDF statements aren't binary, they're tertiary (triples of subject,
> predicate, object), and resources most certainly can have 
> more than one
> value for a given property. I couldn't find a particularly 
> clear example
> like yours in the Primer [1] (is there one? there certainly 
> should be), I
> could only find this way down in the description of containers :
> 
> exstaff:Sue exterms:publication ex:AnthologyOfTime .
> exstaff:Sue exterms:publication ex:ZoologicalReasoning .
> exstaff:Sue exterms:publication ex:GravitationalReflections .
> 
> Here the example is saying : Sue has written "Anthology of Time",
> "Zoological Reasoning", and "Gravitational Reflections". Same 
> subject and
> property with three different objects. As legal as it gets 
> ;-) Note also
> that Sue might have written other things which might be 
> expressed elsewhere
> (e.g. in other RDF files) - there is nothing here to say that 
> this is all
> she's written.
> 
> Cheers,
> Danny.
> 
> [1] http://www.w3.org/TR/rdf-primer
> 
> 
> > -----Original Message-----
> > From: www-rdf-interest-request@w3.org
> > [mailto:www-rdf-interest-request@w3.org]On Behalf Of Tom Reilly
> > Sent: 19 June 2003 18:00
> > To: 'www-rdf-interest@w3.org'
> > Subject: RDF's binary nature
> >
> >
> >
> >
> > Since I first started reading about RDF I assumed its binary
> > nature implied that you couldn't have a resource with more
> > than one value for the same property, ie that this wasn't legal:
> >
> > <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
> >          xmlns="http://www.foo.org/bar#">
> >   <foo>
> >     <bar>baz</bar>
> >     <bar>boo</bar>
> >   </foo>
> > </rdf:RDF>
> >
> > But apparently it is (it validates with the RDF Validation Service
> > and I've encountered real world examples of the same basic 
> structure)
> > and when I think about it there's no real basis for such an 
> assumption.
> >
> > I was hoping someone could verify that this is in fact 
> valid and possibly
> > explain why this is legal when we have bags.  The fact that 
> there are
> > no examples of this in any of the RDF specs I've read (that 
> I can remember
> > at least) could be seen as a little misleading.
> >
> > I'm trying to come up with a simple RDF API and the API 
> could be much
> > simpler if this wasn't the case.  I also realize that this structure
> > is very common in other XML dialects and disallowing it 
> would create a
> > barrier to converting them to RDF.
> >
> > Also if I have:
> >
> >     <bar>baz</bar>
> >     <bar>baz</bar>
> >
> > instead I'm making two distinct but otherwise equivalent 
> statements right?
> >
> > Thanks in advance...
> >
> 
Received on Thursday, 19 June 2003 13:19:35 GMT

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