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Re: Why do we name nodes and not edges?

From: Aidan Hogan <aidan.hogan@deri.org>
Date: Wed, 25 Jul 2012 16:47:02 +0100
Message-ID: <501014F6.1020905@deri.org>
To: semantic-web@w3.org
Steve,

If I understand Melvin's point, in RDF, edge:123456 is the URI of a 
property used to label the edge, not the edge itself.

Analogously, you don't identify a class-instance by it's class URI.

An edge is between two things. It might be directed and it might be 
labelled. In RDF it's both.

Hence, the edge would encapsulate the full triple, including source 
(subject) and target (object) nodes, as well as the label (predicate).

Cheers,
Aidan

On 25/07/2012 16:18, Steve Harris wrote:
> Nothing stops you from giving edges a unique URI, infact I think I've
> worked on systems that did that.
>
> e.g.
>
> <foo> <http://example.com/edge/123456> 1 .
> <http://example.com/edge/123456> a rdf:Property .
> ...
>
> - Steve
>
> On 2012-07-25, at 16:07, Melvin Carvalho wrote:
>
>> Sorry if this topic has been covered before, but I have a question
>> based on the axioms of the web, in particular:
>>
>> *Axiom 0a: Universality 2    Any resource of significance should be
>> given a URI.
>> *
>> In this case we consider the web to be a directed graph (of nodes and
>> edges), where a *node* corresponds to a *resource* but edge does not.
>>
>> We are encouraged to make nodes universal by giving them a URI.
>>
>> Why dont edges get the same treatment, ie encouragment to give it a
>> (universal) name.  Is it even practical?
>>
>> I know there's such thing as reification but that seems to be
>> unpopular (maybe before my time).
>>
>> I'm just curious as to whether this seems asymmetrical, that nodes are
>> seemigly treated in one way, and edges in another?
>
> --
> Steve Harris, CTO
> Garlik, a part of Experian
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Received on Wednesday, 25 July 2012 15:47:35 UTC

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