Re: On Formal IS-A definition
From: paul c <toledobythesea_at_oohay.ac>
Date: Sun, 09 May 2010 16:07:49 GMT
Message-ID: <p5BFn.3719$z%6.79_at_edtnps83>
>
> Here is a quote from (http://en.wikipedia.org/wiki/Zermelo
> %E2%80%93Fraenkel_set_theory)
>
> "ZFC has a single primitive ontological notion, that of a hereditary
> well-founded set, and a single ontological assumption, namely that all
> individuals in the universe of discourse are such sets. Thus, ZFC is a
> set theory without urelements (elements of sets which are not
> themselves sets)."
> ...
Date: Sun, 09 May 2010 16:07:49 GMT
Message-ID: <p5BFn.3719$z%6.79_at_edtnps83>
David BL wrote:
> On May 9, 11:38 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
>> My set of three variables and a dog fully complies with ZFC.
>
> Here is a quote from (http://en.wikipedia.org/wiki/Zermelo
> %E2%80%93Fraenkel_set_theory)
>
> "ZFC has a single primitive ontological notion, that of a hereditary
> well-founded set, and a single ontological assumption, namely that all
> individuals in the universe of discourse are such sets. Thus, ZFC is a
> set theory without urelements (elements of sets which are not
> themselves sets)."
> ...
So? I would like to know what problem arises if a db's attribute values stand for singleton sets instead of 'urelements'. How can that possibly change a dbms' results? How can it prevent Rosie from having properties in common with some variable or other? Would Codd care or just call this technocracy at its silliest? Received on Sun May 09 2010 - 18:07:49 CEST