Relay computers - OR functionality

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Tue Sep 28 19:00:24 2004

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

A set-theorist, I guess. It's acutally a very sensible notation, AND is
much closer to multiplication than addition...

A sort-of way to justify this. If take 0 as false and anything greater
than 0 as true (and some BASICs did just that), then multiplying two
'logical' variables is the way you AND them (if either is false (that is 0),
then the product is 0 and thuse false, if both are true (>0), then the
product is also true), and adding them is the way you OR them (if both
are false (0), then the result is false, if either or both are true, the
result is true).

>
> > These are just symbols until one applies meaning to them. I
>
> Right, but it's hard to work around ingrained meanings that have been with
> you since 1st grade.

The problem is you're confusing addition with AND. They have little to do
with each other.
k
-tony
Received on Tue Sep 28 2004 - 19:00:24 BST