[sc34wg3] Association items

Lars Marius Garshol sc34wg3@isotopicmaps.org
Sun, 12 Jun 2005 16:22:49 +0200

* Murray Altheim
| Actually, "unary name" and "unary occurrence" do sound a bit
| strange, but are accurate descriptions from an ontological modeling
| perspective.

Possibly, but you can't have them in topic maps. They would equate to
a name that is not the name of any topic, or an occurrence that is not
the occurrence of any topic. Neither really makes any sense from a
topic map point of view.

| Unary associations are also called monadic predicates, which are by
| some called "properties" (e.g., Sowa's "Knowledge Representation",
| p469).  Topic names and occurrences are what we call "Topic
| characteristics" but what in the KR/OntEngr field would often call
| properties of the Topic. They are related to the Topic via a monadic
| predicate. 

How can you relate one thing (a name or an occurrence) to another
thing (a topic) with a unary association? Or are the terms "unary
associations" and "monadic predicate" not equivalent?

| Had we decided not to provide the syntactic sugar in XTM, they could
| have been modeled using typed <association> elements.

Provided <association> was extended somewhat.
* Lars Marius Garshol
| You mean that it would be equivalent to
|   is-inquisitive(jan : person, is-inquisitive : characteristic)?
| That seems like a bizarre interpretation to me. Why would we do this?
* Murray Altheim
| Well, that's precisely what we did in ISO 13250 and XTM 1.0. We have
| been calling these things "Topic characteristics" and the relation
| they have with the Topic is a monadic, property relation. As Patrick
| points out, the role is basically characteristic/entity or character-
| istic/Topic (in our case).

I agree with your description of topic characteristics, but I don't
see how that equates to the suggested interpretation I gave above for
unary associations.

Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >