[topicmapmail] relationships: one-way and two-way

[Lars Marius Garshol]

* Simon Grant
>
> But when it comes to occurrences, out there in the world, one can  
> only claim, from one direction, that a particular resource is an  
> occurrence of a topic. That resource itself is not part of the TM,  
> and within the resource, one cannot expect to find any  
> representation of the fact that it is an occurrence of a particular  
> topic, according to a particular topic map.

It's true that in the model there is no "go from resource to topics  
of which it is an occurrence" path that you can follow, but with a  
query language this is dead easy to do. With tolog:

   select $TOPIC from
     resource($OCC, "http://whatever.com"),
     occurrence($TOPIC, $OCC)?

will do what you want.

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