W3C home > Mailing lists > Public > www-rdf-logic@w3.org > June 2002

RE: properties as nodes etc.

From: Danny Ayers <danny666@virgilio.it>
Date: Wed, 19 Jun 2002 09:04:22 +0200
To: "Seth Russell" <seth@robustai.net>, <www-rdf-logic@w3.org>
Message-ID: <EBEPLGMHCDOJJJPCFHEFOEMCGKAA.danny666@virgilio.it>



>Well I'm certainly not a MT authority here.  It seems to me that an arc
>cannot be an object (in an OO sense and also in a RDF sense) unless it has
>some kind of identity ... yet the RDF MT gives it none.  Of course in your
>application there is nothing to prevent you from going outside of RDF
>specifications and providing any kind of identity you like for your arcs.

Doesn't RDFS does give it an identity though - Property subClass of
Resource?

>Reify the triples and then you can give whatever properties you want to the
>reifications.  But bear in mind that doesn't affect the original triples in
>the slightest.

This does sound promising, I'll have a play.

>> In the app I'm working on, I have a (OO) class Item, with subclasses
>Vertex
>> and Edge.
>
>Do you mean that Edge is a subclass of Vertex ?   Personally I dont't see
>how that will ever work.  It seems to me that a Edge is a *partOf* a Vertex
>... or at least that's the way i got it working.   In OO speak can a
>subclass be a part of the parent class?

Heh - actually that isn't what I meant, but someone offlist sent me skeleton
code doing just that. Edge can be a subclass of Vertex, it'd just have all
the characteristics of a Vertex itself, as well as knowing about two other
vertices.

What I've got at the moment is something like this :

   Identifiable (Temporal, Described)
       |
      Item
   /   |   \
Vertex Edge (Adjunct)

Identifiable more or less corresponds to URI - the Temporal (timestamps),
Described (vocabulary stuff) and Adjunct (things like labels, but not part
of the logical graph) interfaces came from forgetting about RDF for a bit
and seeing what the app needed.

>I like your idea of looking at RDF as one interpertation of the graph.  But
>I think you need to give your arcs the property of identity (apart from
>whatever identity they inherit from the vertix of which they form a part).

Yep, they've got it (Identifiable).

>What do you think about how I did it ... see below ?
>
>Seth Russell
>
>language: Semenglish
>sailor
>    seeUrl <http://robustai.net/sailor/> ;
>    language Python.
>(sailor agent theory)
>    seeUrl <http://robustai.net/mentography/Mentography.html>.
>

I *think* this is the kind of thing ... what I have in mind is easy enough
to visualise graphically, you'd just have arcs coming off other arcs, but I
haven't come up with any examples that express this well enough.

Cheers,
Danny.
Received on Wednesday, 19 June 2002 03:11:06 GMT

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