Entity sets - containment and parent-child

[Jason Kraftcheck]

Mark Beall wrote:
> 
> So the only substantial difference between the containment and
> parent-child relationship is that I can ask for the parents of an entity
> set in a parent-child relationship whereas I can't in a containment
> relationship (although the ability to do that would be easy enough to
> add). 

How easy it is to add would depend on the implementation.

> In the containment relationship, the contained sets do play a part
> in the entity set operations, but it would be trivial to ignore them in
> the results.
> 

I'm not sure what you mean.  The contained sets take part in things like
boolean operations.  The effect such operations have on contained sets would
be reflected in the output of getNumEntSets, getEntSets and isEntSetContained.

- jason