Relay computers - OR functionality

[Paul Koning]

>>>>> "Vintage" == Vintage Computer Festival <vcf at siconic.com> writes:

 Vintage> On Tue, 28 Sep 2004, Dwight K. Elvey wrote:
 >> >> In my logic, 'A' would indicated the normally opened contact an
 >> 'a' >> would be the normally closed contact for relay A. I'll use
 >> + to >> indicate OR and . to indicate AND.
 >> >
 >> >You already lost me. You may as well have used ! and $ instead of
 >> A and >a.
 >> >
 >> >:)
 >> >
 >> >P.S. C programming convention (which most people would relate to
 >> >immediately) says that next time you should use & for AND and |
 >> for OR.
 >> 
 >> I'm sorry, people doing logic have been using + and . a lot longer
 >> than C has been using & and |. I specifically stated what I would
 >> use. Look at most any pre-C math book and you'll most likely see
 >> the + and . used for OR and AND.

 Vintage> What Genius decided that + should be OR, as opposed to AND,
 Vintage> which seems actually logical and not counter-intuitive?

 >> These are just symbols until one applies meaning to them. I

 Vintage> Right, but it's hard to work around ingrained meanings that
 Vintage> have been with you since 1st grade.

AND is closer to multiply -- consider that zero times anything is
zero, and zero (false) AND anything is zero.  I believe the notation
comes from mathematics -- group theory (number theory).

      paul