Re: The naive test for equality

"David Cressey" <david.cressey_at_earthlink.net> wrote in message news:7EPIe.1271$Je.157_at_newsread2.news.atl.earthlink.net...
>
> "VC" <boston103_at_hotmail.com> wrote in message
> news:-NCdnQb31ZJFRW_fRVn-gg_at_comcast.com...
>
>> If you are talking about the relational model, one would expect to hear
> the
>> usual first-order terms , like constants, variables, relations etc.
> instead
>> of the fancy words like "reference" and "referent". What is the
>> advantage
>> of using the word "referent" instead of "value" [of some type] or element
> of
>> some set ? In other words, how a "referent", when used in a first-order
>> language, is different form an element of a set ?
>
> I am talking about the representation of "things", and the correspondence
> between operations (like "compare") on the representations, and
> corresponding operations on the things themselves.

So, how do you define a representation ?

 > Hence my use of the word "referent", rather than "value". I don't think
> "referent" is either a fancy word, or superfluous.

How do you define a referent ?

>
> I will correct one piece of terminlogy I used. I said "reference" where
> I
> should have said "representation". That was an error.

See above.

> Everything is a THING.
> Everything inside a data system is a representation.

How do you define a data system ?

Assuming you mean that "a data system" contains "representations", how is this locution different from saying a set contains entities, or everything inside a set is an entity ?

> A representation represents a THING.

Until you give a representation definition, the above is at best unclear. One can speculate that what you have in mind is some theoretical construct representing the real world. If so, then there is a perfectly respectable name for such construct , namely "model".

> Some THINGS are values.
> Some THINGS are not values.

Assuming by values one means elements of some, or another, set, what things are not values ?

>
>
> In particular, I deny that, just because there are things that are not
> values, those things cannot be represented.

For example ?

>> Also, talking about comparing ["checking for equality"] language symbols
>> ("references") is meaningless -- first order formulas, like A = B, are
>> not
>> true or false by themselves, they are so in some interpretation. The
> actual
>> equality/equivalence relation is a set (if it exists) constructed from
>> elements ("referents") of another set.(s).
>
> A = B may be unverifiable (not meaningless)
>
> but
>
>
> 123.45E1 = 12.345E2
>
> is verifiable.

"A=B", or "123.45E1 = 12.345E2", or "2=2", are as meaningless as "dsfsggssg#lkjhg" if taken at their face value as strings of characters.

>
>
>
>
>
>
>
Received on Sat Aug 06 2005 - 00:25:48 CEST