[sc34wg3] SAM: Topic Identity

Murray Altheim sc34wg3@isotopicmaps.org
Thu, 03 Jul 2003 14:11:32 +0100

Lars Marius Garshol wrote:
> * kal@techquila.com
> |
> | Rereading the SAM with CXTM glasses, I notice that the Topic
> | information item does not require any form of identity. Each of the
> | properties [source locators], [subject indicators] and [subject
> | addresses] may be empty as can the [names] property.
> I've been uneasy about this myself, and I do feel that it might be
> that a topic should be required to have some form of identity. RDF
> does not require this, but even so it would make life much easier for
> upper layers (TMQL, say, as well as any other technology that uses
> topic references) if this were required.

Actually, while I agree in principle with the desire for a stated
identity for all topics, by virtue of having a <topic> element in
an XTM document, the topic exists and has identity. This would be
the equivalent of the LTM and XTM expressions


   <topic id="dog"/>

I think this is quite all right, actually, especially as for authoring
purposes, one may *need* to be able to create a valid but empty topic
in order to later populate it. And for simple demonstrations, where the
topic's ID is considered as its identifier, there isn't a huge problem
to be solved here (IMO), e.g.,

   chases([dog] : pursuer, [cat] pursued])

Or are you guys talking about something else and I'm just missing it?


Murray Altheim                         http://kmi.open.ac.uk/people/murray/
Knowledge Media Institute
The Open University, Milton Keynes, Bucks, MK7 6AA, UK                    .

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