[sc34wg3] Questions on N0396: (11) occurence

Lars Marius Garshol sc34wg3@isotopicmaps.org
19 Apr 2003 16:54:49 +0200

* Jan Algermissen
| I (of course) agree with that, but there is one thing that I don't
| understand: In associations in N0396 the 'role playings' are
| recognized as being subjects (represented as association role items)
| but (although an occurrence is understood to be a kind of
| association) in the case of occurrences the 'role playings' are NOT
| recognized to be subjects.
| In other words, N0396 enables me to make statements about the role
| playings in associations but not in occurrences.
| What is the reason for this?

Basically that XTM and HyTM both did it this way. We could extend it
in the SAM to give you features in the data model that you don't have
in the syntaxes, but that seemed sort of pointless. Having explicit
roles is also more costly than not having them, and as far as I know
nobody has ever wanted to use something like this, anyway.

So it is kind of assymetric, but I'm not sure it matters.

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