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Re: Can relvars be dissymetrically decomposed? (vadim and x insight demanded on that subject)

From: Cimode <cimode_at_hotmail.com>
Date: 17 Jul 2006 02:36:58 -0700
Message-ID: <1153129018.098372.91490@b28g2000cwb.googlegroups.com>

Aloha Kakuikanu wrote:
> Cimode wrote:
> > Relations are N
> > dimensional, there is no doubt about that. I refered to projections of
> > relations in a specific point in time.
>
> Time is out of scope of the relational theory.
It is true that time is not the main focus of relational theory in the sense that relations have not been defined according to time. As I said, much work needs to be done in such direction.

> > The topic here is not about the
> > dimensionality of relations: look at the example provided and feel free
> > to bring insight about the topic ;)
>
> Where is the example?

Stated previously...

Consider R1 relvar defining domain DoR1 of values. Each occurence of DoR1 is a member of DoR1.
Consider R1{A1, A2, A3} where D1, D2, D3 are the domains from which A1, A2 and A3 respectively draw and restrict values (through data type definitions). The question is onto *how* R1 can be expressed according to D1, D2, D3 and DoR1....using a simple equation such as the one proposed:

R1 = DoR1 INTERSECT B(DoR1) with B(DoR1) being the ensemble to which belongs ALL D1, D2, and D3. Received on Mon Jul 17 2006 - 04:36:58 CDT

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