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Re: nodes and node labels [was New document: revised version for WG review]

From: Frank Manola <fmanola@mitre.org>
Date: Tue, 30 Jul 2002 09:06:55 -0400
Message-ID: <3D468F6F.60100@mitre.org>
To: Jeremy Carroll <jjc@hplb.hpl.hp.com>
CC: w3c-rdfcore-wg@w3.org

Jeremy Carroll wrote:

> 
> 
> Frank Manola wrote:
> 
>> Jeremy Carroll wrote:
>>
>>> I do not believe that this has any substantive content, but is merely
>>> aesthetic!
>
>>
>> Aesthetic possibly, but it also has implications on apparent 
>> consistency.  
>  
> 
> Agreed. My message wasn't intended to indicate that this would be an 
> acceptable inconsistency at last call. Merely that at this stage it 
> shows stylistic choices in presentation that the WG needs to agree on.


Fine.


> 
> It is clear that the primer editors need to be in on that agreement.
> 
> What other docs talk about the nodes in the graphs and their labels?
> Probably all of them?
> Which use nodes and node labels, which treat the label as the node?
> 


The syntax doc for one;  it talks about URIs labeling the nodes.

 
> 
>>
>> A couple of minor questions about this:
>>
>> a.  if, in the current model theory, some nodes *are* URIrefs, rather 
>> than being *labeled with* URIrefs, why shouldn't arcs *be* URIrefs, 
>> rather than being *labeled with* URI refs?
> 
> 
> Easy one: the nodes can be the label because there is at most one node 
> with any given label. That is not true of arcs. e.g. there are many arcs 
> labelled rdf:type. If we identify the arc with the uriref rdf:type then 
> it has more than two ends.
>


It has more than two beginnings too;  it's a binary relation, after all. 
  This is one of the things we have to explain if we're not going to 
consistently use URIs as labels.

 
> 
>> Well, I think debate is needed, not so much about which explanation is 
>> better, but about whether we ought to use one, and not two (or, heaven 
>> help us, more than two!).  And I think *this* debate ought to happen 
>> ASAP.  It seems to me that if using the basic concepts from the model 
>> theory causes problems for non-mathematicians, we need to explain 
>> things better, not introduce apparent inconsistencies about whether 
>> nodes *are* URIs or are labeled by them (and I suspect that the 
>> non-mathematicians will be the first to notice, and have a problem 
>> with such inconsistencies).
>>
> 
> 
> We clearly should have one, the question is which one?
> 


We agree.

--Frank

 


-- 
Frank Manola                   The MITRE Corporation
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Received on Tuesday, 30 July 2002 08:57:07 EDT

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