Re: 3 value logic. Why is SQL so special?

paul c wrote:
> peter koch wrote:
> > Marshall skrev:
> >
> >> Bob Badour wrote:
> >>> Can we agree that the algebra of nullable<boolean> is not boolean
> >>> algebra and is not 2-valued logic?
> >> Interesting point. On the face of it, any 3VL is not a boolean algebra
> >> because 3 is not a power of two, and all boolean algebras have
> >> a power of two elements. I've long been appreciative of the fact
> >> that, for example, the truth table for AND is 9 cells in 3VL instead
> >> of four for 2VL. And the fact that while there are only 16 distinct
> >> binary functions in 2VL, but, uh, crap. What's that number again?
> >> Oh, yeah: 19683 distinct binary functions in 3VL.[1] So the complexity
> >> goes up a *lot.*
> >
> > Right. I presume you also have problems multiplying two three-digit
> > decimal numbers?
> > ...
>
> Marshall, I believe this is not a question that can be argued on its
> merits, of which to a sensible person there are none. It is futile to
> confront the segment who value great complexity, who likely believe
> submarines will someday swim, whose attitude is basically anti-humanist
> and who present a constantly moving target. Only time can dissolve the
> three-valued concoction. When that happens it will be replaced by some
> other silliness. For consolation, I recommend the book "Voltaire's
> Bastards" by John Ralston Saul.
>
> p

It is surely not a case of whether 3VL is tractable or not, but more a question of why the hell would one want to add complexity where it is unintuitive and unneeded? Received on Fri Sep 22 2006 - 15:34:18 CEST