Re: what are keys and surrogates?

On Jan 14, 8:23 pm, David BL <davi..._at_iinet.net.au> wrote:
> On Jan 15, 9:08 am, Jan Hidders <hidd..._at_gmail.com> wrote:
> > On 14 jan, 03:22, David BL <davi..._at_iinet.net.au> wrote:
> > > On Jan 14, 7:25 am, mAsterdam <mAster..._at_vrijdag.org> wrote:
> > > > David BL schreef:
> > > > > Keith H Duggar wrote:
> > > > >> David BL wrote:
> > > > >>> Keith H Duggar wrote:
> > > > >>>> David BL wrote:
> > > > >>>>> Marshall wrote:
> > > > >>>>>> An interesting note, by the way:
> > > > >>>>>> functions are relations ...
> > > > >>>>> Isn't it more precise to say that the graph of a
> > > > >>>>> function is a relation?
> > > > >>>> No, it isn't.
> > > > >>>>http://mathworld.wolfram.com/Function.html

>


> > In my experience as somebody who works in a Comp. science and


> > Mathematics department the mathematicians that prefer the (D,C,G)

> > definition of a function, also prefer the definition of relation that

> > makes the domains explicit, and so define a binary relation as a

> > triple (D_1,D_2,G). In that case a function is actually again a

> > special case of a relation.  But this is all by no means

> > uncontroversial. If you look at the entry for mathematical relation in

>

>

Finally you were able to admit "that a function is indeed a relation". Sadly you felt compelled to add the nonsense "single work" qualifier in a failed last-ditch attempt to save precise-boy face.

KHD.F6 Received on Thu Jan 17 2008 - 02:39:17 CET