Re: Normalisation

From: Jan Hidders <>
Date: Tue, 12 Jul 2005 21:22:45 GMT
Message-ID: <FwWAe.143403$>

VC wrote:
> "Jan Hidders" <> wrote in message
> news:AyVye.138732$
> [...]

>>Ah, but now you are using the domain or relations, right? There is a 
>>problem with that domain. It doesn't exist. The collection of all 
>>relations is a proper class, and not a set, but domains have to be sets.

> The collection of all relations is most certainly a set, and therefore, a
> domain, domain being a synonym of set. The term "proper class" implies
> that you talk in terms of set theory other than ZF ( Zermelo - Fraenkel ) ).
> There is no need to do so for the reltional model unless you can show there
> is ;)

There is indeed no such need, unless of course you want to define the domain of relations, which you cannot do in ZF.

  • Jan Hidders
Received on Tue Jul 12 2005 - 23:22:45 CEST

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