Re: Question about Date & Darwen <OR> operator
Date: Sat, 3 Sep 2005 15:30:27 -0400
Message-ID: <fKqdnV_XkdJQZITeRVn-sQ_at_comcast.com>
"paul c" <toledobythesea_at_oohay.ac> wrote in message
news:Pb6Se.67282$Hk.4881_at_pd7tw1no...
> the bit on pg 56 ...
> Hs = Hr1 union Hr2
> Bs = {ts: exists tr1 exists tr2
> ( ( tr1 in Br1 or tr2 in Br2) and
> ts = tr1 union tr2 }
>
> ... D & D call it a formal definition. i had the impression they wanted
> to use <AND> and <OR> to define the other operators, such as product from
> that starting point. personally, i like the connection with ordinary
> English, even if i'm often getting the result of <OR> wrong! (maybe that's
> why i like it since so many people i know get the English one wrong too,
> eg. "i'll see you today or tomorrow" usually means neither!)
>
> i was wondering - if you started with 'cross product' instead of <OR>, how
> would you define 'cross product'?
>
> thanks,
> pc
Received on Sat Sep 03 2005 - 21:30:27 CEST