Re: RA with MV attributes
From: paul c <toledobythesea_at_oohay.ac>
Date: Sat, 20 Jan 2007 01:28:52 GMT
Message-ID: <ofesh.707375$5R2.47345_at_pd7urf3no>
>
>
> 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.
> ...
Date: Sat, 20 Jan 2007 01:28:52 GMT
Message-ID: <ofesh.707375$5R2.47345_at_pd7urf3no>
David wrote:
> paul c wrote:
>
>>David wrote: >> >>>paul c wrote: >>>... >>> >>>>I do think that once one has a definition it is important to proceed to >>>>positioning it in the scheme of things, for example is this a physical >>>>approach for storing two relations in one or is it an attempt to promote >>>>three-valued logic or is it something else? >>> >>> >>>I'm interested in both its logical and physical aspects. It seems >>>best initially to focus mainly on the logical. >>>... >> >>I could entertain this if the motive were to formalize a physical >>storage scheme. But I don't see anything logical about presenting to a >>user the inference that fred and bill own an empty set of cars that are >>green
>
>
> 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.
> ...
p Received on Sat Jan 20 2007 - 02:28:52 CET