Re: Notions of Type

From: paul c <toledobythesea_at_oohay.ac>
Date: Sat, 19 Aug 2006 17:45:07 GMT
Message-ID: <D6IFg.424208$iF6.157341_at_pd7tw2no>


Marshall wrote:
> ...
> The Tropashko algebra's operators ARE commutative,
> and associative, and absorbitive and idempotent
> to boot! And semi-distributive as it turns out. And
> there's only two of them. Now THAT is an algebra
> for you!

I don't mean to criticize TA's motivation for the simple reason that I'm not competent to talk about lattice algebra properties.

But a perhaps trivial comment is that D&D claim their algebra can also be reduced to two operators as well, take your choice, NAND and REMOVE or NOR and REMOVE.

For some reason I want to compare TA to D&D algebra, maybe this is wrong-headed but I do see a similarity in the two approaches, what D&D call 'treating operators as relations', for example TA seems to apply this idea to projection, whereas D&D use it to get rid of operators like EXTEND and SUMMARIZE, if I recall right.

p Received on Sat Aug 19 2006 - 19:45:07 CEST

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