Re: RM formalism supporting partial information

From: Marshall <marshall.spight_at_gmail.com>
Date: Fri, 16 Nov 2007 09:44:59 -0800 (PST)
Message-ID: <d24a2c59-4052-4c8a-95ee-5db68ad53479_at_b40g2000prf.googlegroups.com>


On Nov 15, 9:45 am, David BL <davi..._at_iinet.net.au> wrote:
> On Nov 16, 1:46 am, Marshall <marshall.spi..._at_gmail.com> wrote:
>
>
>
> > 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.
>
> I apologise then.
>
> When you said
>
> > So you can have two different attributes
> > with the same name.
>
> I assumed you meant that my definition was poor because it allowed two
> different attributes to have the same name.
>
> I admit I have no idea what you mean by distinguishing between "is"
> and "has".
>
> In natural language I'm comfortable with saying that an attribute
> *has* a name and domain, or with saying that an attribute *is* a
> composite of a name and domain, or an attribute *consists* of a name
> and domain. IMO all of these are equally valid informal
> descriptions.
>
> Please tell me what you actually think and how it relates to what you
> actually said!

Sorry to take so long in replying. Actually it was just a more or less offhand comment about

  For attributes a1,a2, a1 = a2 <=> N(a1) = N(a2) and D(a1) = D(a2)

I had a hard time reading your paper and didn't make it to the end. But Jan had the much better critique.

Marshall Received on Fri Nov 16 2007 - 18:44:59 CET

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