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Re: How can I proove associtivity of natural in relational algebra?

From: Filter911 <filtermedialtd_at_gmail.com>
Date: 21 Nov 2005 13:22:57 -0800
Message-ID: <1132608177.118486.76820@g14g2000cwa.googlegroups.com> 






Mikito Harakiri wrote:


> Filter911 wrote:

> > Can someone give me a link for a full proof or something?

>

> Given relations A,B, and C, expand each realtion into a (possibly

> infinite) relations A', B', and C' with the same set of attributes

> (which is the union of the attribute sets for A, B, and C). Then, the

> join of A, B and C is the intersection of A', B', and C'. Intersection

> is associative.




What do you mean by "expand each relation"?



Thanks
Received on Mon Nov 21 2005 - 15:22:57 CST












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