Re: more closed-world chatter

paul c wrote:
> (Aside - it appears to me that you and Bob B are more or less on the
> "same page"

I think so.

> when it comes to the advantage of sub-typing in dealing with
> my question.

I don't know about "advantage"; I just don't see how you can avoid it.

> Also, for some reason I can't explain very well, I seem to
> view types or domains in a very mechanical way meaning that if a user
> can define a type that user could also re-define a type which might
> invalidate all of an existing db's "propositions".

Sounds perfectly reasonable. Isn't this just (like) the user changing any constraint on a database? It might conflict with existing data (and I would suggest the modification in that case be rejected).

-- 
Jon