Re: constraints in algebra instead of calculus
Date: Tue, 19 Jun 2007 07:59:28 -0700
Message-ID: <1182265168.282522.303950_at_n15g2000prd.googlegroups.com>
On Jun 19, 12:59 am, Jon Heggland <jon.heggl..._at_idi.ntnu.no> wrote:
> Vadim Tropashko wrote:
> > R <AND> (R RENAME B as B') )
> > IS
> > R WHERE B = B'
>
> > where the "IS" symbol is relational equality. Relational equality (aka
> > "IS") provides a succinct way to say that the symmetric difference of
> > the relations
>
> > R <AND> (R RENAME B as B') )
>
> > and
>
> > R WHERE B = B'
>
> > is empty.
>
> Forgive me if I'm not paying attention, but why do you need a special
> symbol and explanation for relational equality? Why can't you just use =?
What is the syntax to disambigute the relational equality from the equality symbol in the identity relation? OK, extra brakets would do, so how about this:
( R <AND> (R RENAME B as B') ) ) = (R <AND> (B = B')) Received on Tue Jun 19 2007 - 16:59:28 CEST