Re: what are keys and surrogates?
Date: Mon, 14 Jan 2008 19:51:48 GMT
"vldm10" <vldm10_at_yahoo.com> wrote in message
> On Jan 13, 4:41 pm, "David Cressey" <cresse..._at_verizon.net> wrote:
> > "David BL" <davi..._at_iinet.net.au> wrote in message
> > > This however doesn't change the fact that most authors define a
> > > (mathematical) relation as a set of ordered tuples, which means a
> > > function is not a relation (assuming, as most do, that a function has
> > > a defined domain and codomain).
> > I don't understand how the conclusion follow from the premise.
> I am afraid that you don't understand above conclusion because you
> don't understand what function is.
What makes you think that? Received on Mon Jan 14 2008 - 20:51:48 CET