[sc34wg3] TMDM bug

Geir Ove Grønmo sc34wg3@isotopicmaps.org
Thu, 03 Feb 2005 11:08:00 +0100

On Thu, 03 Feb 2005 10:57:03 +0100, Lars Marius Garshol  
<larsga@ontopia.net> wrote:

> * Geir Ove Grønmo
> |
> | 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].

Yes, I meant [reified].

> 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.

Great. I'm happy. :)

Geir O.