Re: What to call this operator?

paul c wrote:
> if that's right, then i am a bit happier about <or> in that it doesn't
> seem to give the same result of <and> (although i can't think of a good
> reason right now for objecting to that).

Your intution is quite right: it would be very suspicious if they produce the same result. <OR> and <AND> are dual in the "normal" boolean algebra, so that the only time when they produce the same result is when the first argument is the same as the second one. Once again, relational algebra is not boolean. The notion of duality, however, still has a well defined interpretation in the Lattice model. Received on Tue Jun 28 2005 - 23:59:49 CEST