Request for Comments: Filter behavior on undefined values

[Martin Mares]

Hello!

> Assuming NOT is NEG [...]

Yes.

> [...] and conditionals fail for non-true.

In Sherlock, we had three-way conditionals: if the condition was
undefined, neither the "then" nor "else" branch was executed, but
there could be an additional "undefined" branch. In retrospect,
this probably wasn't a good idea, although it followed the three-way
logic better.

> Note that this is not Boolean
> algebra (as law of excluded middle is not satisfied), but De Morgan
> algebra, so perhaps we could also rename boolean datatype to de_morgan
> datatype ;-) .

;-)

				Have a nice fortnight
-- 
Martin `MJ' Mares                          <mj at ucw.cz>   http://mj.ucw.cz/
Faculty of Math and Physics, Charles University, Prague, Czech Rep., Earth
Homo homini lupus, frater fratri lupior, bohemus bohemo lupissimus.