Re: relational algrabra division?
From: James K. Lowden <jklowden_at_speakeasy.net>
Date: Sat, 13 Dec 2014 14:10:27 -0500
Message-Id: <20141213141027.f5431935.jklowden_at_speakeasy.net>
Date: Sat, 13 Dec 2014 14:10:27 -0500
Message-Id: <20141213141027.f5431935.jklowden_at_speakeasy.net>
On Fri, 12 Dec 2014 02:33:22 -0500
ruben safir <ruben_at_mrbrklyn.com> wrote:
> The DIVISION operation can be expressed as a sequence of ?, ×, and ?
> operations as
> follows:
> T1 ? ?Y(R)
> T2 ? ?Y((S × T1) ? R)
> T ? T1 ? T2
>
>
> tried this and go some insite but it is still just magic
You may find this helpful.
http://fie-conference.org/fie2003/papers/1057.pdf
--jkl Received on Sat Dec 13 2014 - 20:10:27 CET