Re: Constraints and Functional Dependencies

On 25 fév, 13:03, mAsterdam <mAster..._at_vrijdag.org> wrote: [Snipped]
>
> But what exactly is the reference referencing?
> A set of S-tuples, not just one.
> That makes it a sort of hand_wave instead of a reference, right?
>
> Is there something I am missing?
Maybe the preeminence of RA domain associative characterization over structuralist perspective based on attributes.

> <handwave>
> (i a)
> A relation R with attribute a (written as R(a)) having
> a as a handwave into S(b)
> is expressed as follows:
>
> forall R(a): exists S(b): a = b
>
> Note that b need not be a ck to S, hence 'into', not 'to'.
> </handwave>
Again, attribute-based characterization of domains and relations leads to a conceptual dead end and a circular argumentation about key (As you can see). Pulling out of it requires effort. It seems however that this perspective and the proof of it ellludes some of the audiences. I do not know how to express it better than I did. Received on Sun Feb 25 2007 - 13:27:36 CET