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Re: "tdb" and "duri" URI schemes...

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Fri, 5 Nov 2010 04:38:35 -0400
Message-ID: <AANLkTi=R3kbN8MeCq+joLbhqW9asTCittC+KHTef4u0N@mail.gmail.com>
To: Larry Masinter <masinter@adobe.com>
Cc: Jonathan Rees <jar@creativecommons.org>, W3C TAG <www-tag@w3.org>
On Fri, Nov 5, 2010 at 4:13 AM, Larry Masinter <masinter@adobe.com> wrote:
>   FWIW, I can't understand what you are talking about here.
>
> you seem to, or at least your argument seems to accept the terminology
> anyway.

I'm doing my best to communicate. That I accept terms you use as
meaningful doesn't mean I accept the sentences you make from them as
such.

>   Even if there was a counting argument to be made here, I can't see how
> you would arrive at "things that *can* be described". You might perhaps land
> up with "things that *have* been described". But there isn't a unique
> mapping of countable on to uncountable sets.
>
> I don’t really think it’s necessary to get into a debate about determinism,
> I’m just trying to justify my choice of wording here. I say “things that can
> be described”, and Jonathan said it is “silly and meaningless”. I disagree
> that the distinction is either “silly” or “meaningless”, even if it doesn’t
> match your (or his) world model.

It's "silly" because it doesn't have a constructive impact and because
it suggests a bad thinking habit - namely that there are two
categories of things, somehow intrinsically different - those that can
and those that can't be described. Whether you intend this
interpretation or not, this is what the language you use suggests.

Whether it is meaningful is still unclear to me. We don't have to
debate determinism, but you should be consistent in your language. If
your argument depends on determinism then call the set "things that
will be described". If not, explain what you mean by "can".

>  At least, for me, the distinction isn't silly or meaningless. In addition,
> the notion of "identity" is
> associated with the description rather than the thing-described
>
>  Which notion of identity? There are a
> number. http://plato.stanford.edu/entries/identity/
>
>   There are certainly notions of identity associated with (any)things.
>
> Perhaps you can explain how I can talk about identity of things without
> having a way of talking about the things whose identity is in question.

Are we not able to talk about the identity of real numbers, despite
the fact that there are uncountably many, and therefore by your
account we can't possibly describe all of them?

(answer: yes)

>   That is, "things" don't really form a set, in the sense of having a clear
> equality relationship.
>
> Set theory requires you to know that the elements of a set are distinct.
> Either a = b or a != b.  Unless you can identify a or b, you can’t even ask
> whether they are the same.

Set theory doesn't ask whether elements are the same. It doesn't ask
you to identify anything. There are things. There can be sets of them.
The structure of the set is such that no thing appears more than once.

We are perfectly able to create the set of real numbers in the
interval [0,1], despite that in the framework you present we don't
have enough descriptions (which are countable by your assertion) to
"identify" all the a's and b's.

> I'd be interested in an attempt to be convinced. But as another heads up,
> what you are saying here seems in contradiction to the basis of all the
> SemWeb languages, which I think would be setting precedent.
>
> I can’t imagine what this means. If you have something in specific you think
> I’m contradicting, please point it out.

http://www.w3.org/TR/rdf-mt/#urisandlit

"The semantics treats all RDF names as expressions which denote. The
things denoted are called 'resources', following [RFC 2396], but no
assumptions are made here about the nature of resources; 'resource' is
treated here as synonymous with 'entity', i.e. as a generic term for
anything in the universe of discourse."

http://www.w3.org/TR/2009/REC-owl2-syntax-20091027/#Real_Numbers.2C_Decimal_Numbers.2C_and_Integers

"The datatypes owl:real and owl:rational are defined as follows.

Value Spaces.

The value space of owl:real is the set of all real numbers.
The value space of owl:rational is the set of all rational numbers. It
is a subset of the value space of owl:real, and it contains the value
space of xsd:decimal (and thus of all xsd: numeric datatypes listed
above as well)."

So the universe of discourse includes real numbers, which are
uncountable. Your restriction of the domain of discourse to any
countable set ("things that can be described" distinguished by being
countable) contradicts this precedent.

-Alan
Received on Friday, 5 November 2010 08:39:24 GMT

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