[sc34wg3] TMCL 6.7 Overlap Declaration

[Lars Marius Garshol]

* Steve Pepper
>
> The point to be made is that if this kind of overlap is the most  
> common, then the mechanism provided by TMCL for overriding the  
> default is suboptimal. The reason for this is that TMCL requires  
> every pair of non-disjoint types to be specified separately.

Actually, it doesn't, although you need to read the draft very  
carefully to see it. The template uses only two overlaps associations,  
but there's nothing to stop you from putting in more. Indeed, the  
schema says:

tmcl:overlap-declaration isa tmcl:topic-type;
   # ...
   plays-role(tmcl:allows, tmcl:overlaps, 2, *);
   # ...

The global validation rule in 6.7 has been written in such a way that  
it works for any number (greater than 1) of overlaps associations on  
the same declaration.

> For example, the topic type Instrumentalist is divided into 20  
> subtypes (from Bassist to Violinist) in the topic map Tapsa's  
> Concerts (see
> http://www.ontopedia.net/omnigator). In order to allow for the fact  
> that any given player might play two different instruments it would  
> be necessary to make 20! (factorial 20) TMCL declarations: one for  
> each possible pair. That is 2,432,902,008,176,640,000 declarations!

It's actually only half of that.

--Lars M.
http://www.garshol.priv.no/tmphoto/
http://www.garshol.priv.no/blog/