[sc34wg3] TMCL 6.7 Overlap Declaration

Steve Pepper pepper.steve at gmail.com
Mon Jun 22 11:26:02 EDT 2009

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* 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.

So, in the case I cited, I would need to:

(1) define a new template that allows 20 overlaps associations
(2) call that template and specify all 20 subtypes of Instrumentalist


If this is true, it is clearly better than having to specify 20! pairs of topic
types. But it is still too much work when creating a TMCL schema (especially
since there may well be multiple types whose subtypes are not disjoint).

Viewed from a maintenance perspective it is also more work than it needs to be:
Each time a new subtype is added to the ontology, both the template and the call
to the template have to be modified. That shouldn't be necessary. Instead it
should be possible to declare the following

	tmcl:non-disjoint-subtypes( on:Instrumentalist )

and be done with all current (and future) subtypes of Instrumentalist.

Will the editors consider adding something along these lines?

PSI: http://psi.ontopedia.net/Steve_Pepper
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