[sc34wg3] Illustrating SIDPs

[Robert Barta]

On Mon, May 17, 2004 at 01:07:57PM +0100, Ann Wrightson wrote:
> Robert/Patrick said:
> 
> > 
> > TMCL is a language which allows to define constraints C ala "a + b >
> > c".  Our concrete universe is the set of possible topic maps M.  A
> > TMCL constraint C then validates against a map m (element from M)
> > under particular conditions as is defined by the TMCL semantics.
> >
> 
> The question I would have is what defines your:
> 
> "concrete universe is the set of possible topic maps M."
> 
> Seems to me that if we take seriously the claim that a subject is 
> anything, anyone would want to say...., then you have a fairly large 
> universe to deal with. Or is there some subset that you intend to address?

Ann,

I talked about the "set of topic maps", not the "set of subjects".

If we assume the existence of a 'real world' (not an overly attractive
thought in these days, I would mean), then the topics are just
placeholders and their arrangement in a topic map is just what the
author thinks how they should be arranged.

So a map does NOT include the subjects.

Still the set of TMs is infinite. But, hey, so what?

> I say:
> 
> I think Robert meant to talk about the things that are topic maps
> (considered as maps) - a universe that includes at least TMDM-compliant
> topic maps - and to exclude from M those things that (although they may be
> named in or referenced from topic maps) are not topic maps.

'TMDMness' is here a secondary concern. More important is that the
formalism is manageable and that it can be used for practical
purposes. Otherwise it remains a finger exercise.

In my view (some might disagree) a formal model is much closer to
TMRM. Only in a second step I would try to express the additional
constraints which TMDM imposes. That way TMDM is grounded and we still
have a decent way to express the functionality needed for TMQL/TMCL.

\rho