Re: Thinking about MINUS

paul c wrote:
> Marshall wrote:
> ...
> > Ah, but when we are joining, which is to say unifying, two relations,
> > and the two relations each make different, *incompatible* claims
> > about the type associated with a particular attribute name, then
> > I would say that well meets the criteria for being "contradictory."
> > ...
>
> Well, if I have 10 Navel Oranges and 10 Tangerine Oranges and I ask how
> many Florida Oranges I've got, I would hope the answer would be zero,
> not "contradiction".

This is why the concept of type (or domain) is not such a great idea. Received on Mon Jan 08 2007 - 18:22:26 CET