Re: TRUE and FALSE values in the relational lattice
From: Vadim Tropashko <vadimtro_invalid_at_yahoo.com>
Date: Thu, 21 Jun 2007 10:51:06 -0700
Message-ID: <1182448266.868977.167490_at_e9g2000prf.googlegroups.com>
Date: Thu, 21 Jun 2007 10:51:06 -0700
Message-ID: <1182448266.868977.167490_at_e9g2000prf.googlegroups.com>
On Jun 21, 7:12 am, Marshall <marshall.spi..._at_gmail.com> wrote:
> I would be interested to have the axioms for division
> especially.
Here is a cute identity involving set equality join (not division!),
and equality relation:
((R /=\ E) /=\ E ) = R
where the "/=\" is a symbol for set equality join.