Re: RA with MV attributes

On Jan 19, 4:12 pm, "David" <davi..._at_iinet.net.au> wrote:
> That's an incorrect inference. That's not what a tuple means. If you
> have the tuple
>
> Names = {Fred, Bill}, Cars = {}, CarColour = {green}
>
> Then you are meant to read out propositions by taking the cross product
> of the sets. The cross product is of course empty.

"meant to read out propositions by taking the cross product?" Says who?

Anyway, that doesn't make a lot of sense. It introduces a new discipline, tuple normalization, because the tuple

  Names = {Fred, Bill}, Cars = {}

has the same information content as

  Names = {}, Cars = {}

Why does having RVAs mean I have to introduce this new semantics for tuples? What was wrong with the old one?

Marshall Received on Sat Jan 20 2007 - 01:46:48 CET