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Re: Why do we name nodes and not edges?

From: Steve Harris <steve.harris@garlik.com>
Date: Wed, 25 Jul 2012 17:08:30 +0100
Cc: semantic-web@w3.org
Message-Id: <DF82F1CD-F698-4100-A2AE-96092E29BF02@garlik.com>
To: Dave Reynolds <dave.e.reynolds@gmail.com>
Yes, exactly, I was writing in a bit of a hurry, maybe a UUID would make made it clearer.

- Steve

On 2012-07-25, at 17:04, Dave Reynolds wrote:

> If I understand Steve's point he was meaning that you can mint a new unique edge:xxxxxx identifier for each edge.
> 
> [Presumably you could make that a subPropertyOf the actual property you wanted to assert.]
> 
> Cheers,
> Dave
> 
> On 25/07/12 16:47, Aidan Hogan wrote:
>> 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
>>> +44 7854 417 874 http://www.garlik.com/
>>> Registered in England and Wales 653331 VAT # 887 1335 93
>>> Registered office: Landmark House, Experian Way, Nottingham, Notts,
>>> NG80 1ZZ
>>> 
>> 
>> 
> 
> 

-- 
Steve Harris, CTO
Garlik, a part of Experian
+44 7854 417 874  http://www.garlik.com/
Registered in England and Wales 653331 VAT # 887 1335 93
Registered office: Landmark House, Experian Way, Nottingham, Notts, NG80 1ZZ
Received on Wednesday, 25 July 2012 16:08:59 UTC

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