[REBOL] Re: What is Mathematics?
From: jeff:rebol at: 3-Jul-2001 12:26
Howdy, Joel:> As another example, the algebraic law that lets me refactor > > if any [a <= b none? find p q not same? x y] ... > > into > > if all [a > b find p q same? x y]maybe into: if NOT all [ a > b find p q same? x y ] ... DM is ~(p or q) = ~p and ~q ~(p and q) = ~p or ~q Working backwards, though: ~( ~p and ~q ) == ~(~(p or q)) [DM] == (p or q) [Double negation] Therefore: (p or q) == ~ ( ~ p and ~q ) :-) -jeff