Re: DAML: restricting number of elements in a list

The daml:item property relates a list to each of its elements.  One can
impose a daml:minCardinality restriction on the daml:item property to
ensure that the number of vertices in a polygon is at least 3. 

Ken Baclawski
Ken@Baclawski.com
UBOT Project

On Wed, 6 Feb 2002, Steven Gollery wrote:

> I'm working on an ontology in DAML that includes some geometric
> concepts. I would like to be able to somehow define a property Vertices
> whose domain is the Polygon class and whose range is ordered collections
> of instances of the Point class, where the length of the ordered
> collection is at least three.
> 
> It would be fairly straightforward to say that each Polygon must have at
> least three values of a Vertex property which is restricted to class
> Point, but that would lose the idea the vertices have an order -- the
> order is obviously a fundamental part of the semantics for the polygon.
> 
> Does DAML provide any way to restrict the number of elements in a list?
> Or is there some other way to do what I need here?
> 
> Thanks in advance,
> 
> Steve Gollery
> sgollery@cadrc.calpoly.edu
> 
>