On Wed, Feb 20, 2002 at 07:04:44PM +0000, Nick Ing-Simmons wrote: > Brian Lee Ray <[EMAIL PROTECTED]> writes: > >From: "Nicholas Clark" <[EMAIL PROTECTED]> > >Sent: Tuesday, February 19, 2002 3:15 PM > >Subject: De Morgan's theorum > >> I have remembered the name correctly, haven't I? > >Yes. If we were really serious about optimizing logical expressions, > >we would probably want to use Karnaugh maps. > > Karnaugh maps are for Humans with visual ways of understanding. > There is an easy-to-code Algorithm (Quine McLusky?) which does > the job for computers - it it can handle what would be (projection of) > an n-Dimensional hyper cube of a Karnaugh map.
Unfortunately this problem is NP-complete and Quine-McClusky is an exact algorithm. A heuristic algorithm like espresso might be better, but > >However, I just don't > >think most programs spend enough time doing logical comparison to > >really matter. Besides which, such techniques work best on complex > >expressions, which are rare indeed. I suspect this is true. -- Paul Johnson - [EMAIL PROTECTED] http://www.pjcj.net
