[sc34wg3] TMDM bug

Lars Marius Garshol sc34wg3@isotopicmaps.org
Thu, 03 Feb 2005 10:57:03 +0100

* Geir Ove Gr=F8nmo
| I agree that it might be worth having, but I'm a bit unsure about
| whether it makes sense for the [reifier] property to contain another
| topic.  Shouldn't the topics be merged instead? Or is the reason
| that they are not *automatically* merged that the TMDM does not
| impose merging unless the application really want to?

The [reifier] property is on all item types except topics, and
contains the reifying topic, so I guess you mean [reified].=20

TMDM is actually cleverly written in such a way that [reified] can
never contain another topic. The rule for [reified] is that for
topic X it contains the item Y where

  exists(Z) | Z in Y.[source locators] and Z in X.[subject identifiers]

However, by the equality rule for topics, if Y were a topic it would
have to merge with X, and so Y can never be a topic.

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