Relay computers - OR functionality

From: Paul Koning <pkoning_at_equallogic.com>
Date: Tue Sep 28 14:01:30 2004

>>>>> "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
Received on Tue Sep 28 2004 - 14:01:30 BST