Fredrik Lundh <[EMAIL PROTECTED]> wrote: > Marcin Ciura wrote: > > >>>all(flying elephants which are not pink) => true > >>> > >>>So, these flying elephants -- are they pink or not? > >> > >> No, you ask two different sets whether they are true. > > > > No, there is only one empty set. > > who said anything about empty sets ?
Universally-false predicate <--> empty set ...in Cantor's/Frege's world, which is commonly accepted as equivalent to Aristotle's Logic. Modal logic is a different kettle of fish (and, in retrospect, what Dodgson [aka Carroll] was groping towards)... but I know of no programming paradigm based on it (even Turing's and Church's map more easily to naive set theory//logic, give or take a Zermelo or so;-). I would in fact challenge the assertion that a useful programming paradigm COULD be based on modal logic, hoping for proof of the contrary;-) Alex -- http://mail.python.org/mailman/listinfo/python-list
