[topicmapmail] generate hierarchical GUIs from all transitive associations

[Lars Marius Garshol]

* Conal Tuohy
| 
| In the earlier thread about class-subclass and class-instance
| relations, I was also inspired to dig out my old algebra text books.
| It seems to me useful to categorise associations in terms of the
| properties of binary relations, such as symmetry, anti-symmetry,
| transitivity, reflexivity, etc.

Yes, this is something that would be very useful, and which is just
waiting to be picked up by someone and done. There definitely remain
some useful papers to be written in this area.

| Transitivity at least is recognised in the XTM spec with a PSI:
| http://www.topicmaps.com/xtm/1.0/template.xtm#assoc-prop-transitive

Well, actually, it's not part of the XTM spec. There are no references
to it from that spec, it's just a file that happens to reside in the
same directory. *Why* it is there I have no idea.

| - it's possible to annotate any association topic as having this
| property, 

Well, the XTM file given on the topicmaps.org site is not complete: it
doesn't tell you how to *use* this published subject. The associated
HTML file[2] does give a hint, but unfortunately that hint is
nonsensical. 

| [...] and then use this knowledge e.g. in your UI: the issue that
| came up earlier, of selecting which associations should appear as a
| hierarchy in a UI, breadcrumbs, etc, can then be dealt with
| automatically: an association type is suitable if it is transitive
| and hence represents some kind of ordering. 

Now this is true. We've been thinking of adding this functionality to
the Omnigator for a while now, but have so far not gotten round to it.
I do agree it would be useful.

[2] <URL: http://www.topicmaps.com/xtm/1.0/template.html >

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