Re: Distributivity in Tropashko's Lattice Algebra

From: vc <boston103_at_hotmail.com>
Date: 17 Aug 2005 12:17:42 -0700
Message-ID: <1124306262.700300.96090_at_f14g2000cwb.googlegroups.com>


vc wrote:
> Mikito Harakiri wrote:
> > VC wrote:
> > > "Mikito Harakiri" <mikharakiri_nospaum_at_yahoo.com> wrote in message
> > > news:1124225375.601615.162210_at_g47g2000cwa.googlegroups.com...
> > > >
> > > > vc wrote:
> > > >> A union '00' = '00'.
>
> Sorry, I meant A union '00' = '01', of course. Was confused by your
> unorthodox union.
>
> > There is another argument against
> >
> > A union 00 = 00
> >
> > For any two relations A and B, the relation
> >
> > A union B
> >
> > has cardinality bigger than both A and B. In you proposition this
> > property is lost.
>
> Right. See above.
>
>
>
> To sum up, the three '1' '0' combinations are :
>
> 00 union A = 01
> 00 join A = 'a0' where 'a' is A's set of attrs.
>
> 01 union A = 01
> 01 join A = A
>
> 10 union A = A
> 10 join A = 10

A revision ;)

The first expression is not good yet. It should be:

00 union A = 0x, where x is either 0 or 1 depending on whether A is empty or not. Received on Wed Aug 17 2005 - 21:17:42 CEST

Original text of this message