Re: Distributivity in Tropashko's Lattice Algebra

From: VC <boston103_at_hotmail.com>
Date: Thu, 18 Aug 2005 01:03:51 -0400
Message-ID: <ROOdnf5FiLwvi5neRVn-rw_at_comcast.com>


"Marshall Spight" <marshall.spight_at_gmail.com> wrote in message news:1124330666.830088.270470_at_g44g2000cwa.googlegroups.com...
> Sorry I'm so far behind on this thread. It'll get worse, too
> as I'm on vacation starting tomorrow.
>
>
> Vadim Tropashko wrote:
>>
>> In D&D algebra
>>
>> A union DEE != A
>> A union DEE != DEE
>> A join DEE = A
>>
>> A union DUM = A
>> A join DEE != DEE
>> A join DEE != A
>
> This is not my understanding. I was under the impression
> from TTM that
>
> A <OR> DUM = A
> A <OR> DEE = A
> also
> A <AND> DUM = header(A)
> A <AND> DEE = A
>
> (Using <AND> and <OR> to refer specifically to the TTM
> algebra.)
>
>
>> > > Now, the novelty is that there is a *third* special element 00 the
>> > > relation with with arity = 0 and cardinality = 0, which is not a unit
>> > > in Relational Lattice. It is a mapper of a relation into a header
>> > > relation!
>
> I thought arity 0, cardinality 0 described DUM. Is that not so?

Yes.

> It is possible I'm miscalibrated again.
>
>
> Marshall
>
Received on Thu Aug 18 2005 - 07:03:51 CEST

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