Re: RM formalism supporting partial information

On Nov 14, 9:12 pm, David BL <davi..._at_iinet.net.au> wrote:
> On Nov 15, 10:01 am, Marshall <marshall.spi..._at_gmail.com> wrote:
>
>
>
> > On Nov 14, 2:21 pm, David BL <davi..._at_iinet.net.au> wrote:
>
> > > On Nov 15, 1:20 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
> > > > paul c wrote:
> > > > > David BL wrote:
> > > > > ...
>
> > > > >>http://www.members.iinet.net.au/~davidbl/MVattributes.doc
>
> > > > >> This is still a work in progress.
>
> > > > >> I welcome any comments.
>
> > > > By the second paragraph, the document entered into the realm of
> > > > nonsense, and I stopped reading.
>
> > > An attribute has a name and a domain. How is that nonsense?
>
> > You didn't say an attribute *has* a name and a domain. You said
> > an attribute *is* a name and a domain. So you can have two
> > different attributes with the same name.
>
> I said an attribute *consists* of a name and a domain. That is
> compatible with saying an attribute has (and only has) a name and a
> domain. I assume you're not making some philosophical point about
> the sum being greater than the parts; IMO distinguishing between
> "has" and "is" is splitting hairs. In natural language at that!
>
> Seeing as you're likely to try to interpret mathematical structures in
> terms of words like "has" and "is", I must point out that
> mathematical structures do not exclusively own their "parts". For
> example the point (10,15) in R^2 doesn't exclusively own the integers
> 10,15 (ie they can be used for other things!). Similarly an attribute
> doesn't exclusively own it name or its domain. In keeping with the
> spirit of mathematical formalism I didn't say that an attribute has a
> domain-name - instead it has a domain. Formally that only means
> there exists a mapping D from attribute x to domain D(x).
>
> You cannot state that all attributes have different names. That would
> be nonsensical because universal quantification is only meaningful
> with respect to some defined set over which it quantifies. At the
> point of definition of "attribute" there is no such set to quantify
> over. I find it curious that you appear to allow a mathematical
> realism philosophy to invade mathematical definitions.
>
> In the document I (correctly) said nothing about unique names until
> defining a relation.

You attribute a bunch of positions here to me, but none of them are things that I actually think or things that I actually said.

Marshall Received on Thu Nov 15 2007 - 17:46:10 CET