Re: Language = Namespace. was: How namespace names might be used

At 15:58 19/06/00 -0400, Tim Berners-Lee wrote:

>- a languge is (here) the set of names, their constraining syntax, and a
>defined meaning for any combination of names which satisfies those
>constraints on syntax.
>
>- a namespace corresponds to a language.  I know that some don't want this
>model but honestly without it all work on XML should stop immediately and be
>restarted with a proper footing. What is XHTML? a Language! That is actually
>what the letter stands for. There is meaning in it.  The meaning is NOT
>carried by out of band discussion, it is carried in the XHTML specification.

I'm still struggling to understand this vision.  In the example:

<a:a xmlns:a="http://a.com">
<b:b xmlns:b="http://b.com">
</b:b>
</a:a>

Do we have:

(a) A document written in one language using the set of names 
{http://a.com}a, {http://b.com}b.  This seems to be the natural 
interpretation of Tim B-Ls first paragraph.

(b) A macaronic document written in two languages.  This is how I interpret 
the second paragraph.

(c) A document which, although legal according to the namespace REC, 
doesn't conform to the vision of how the web will be built, and therefore 
doesn't need to be considered.  I sincerely hope that this is _not_ the case.

I _suspect_ that Tim-BL will answer (b), but I think that many of us 
(myself, certainly) have been thinking in terms of (a).

The important difference, it seems to me, is whether metadata is more 
usefully associated with a type (a) language or a type (b) language.  Will 
you ever need to make statements about an element which apply only in the 
context of another element from a different namespace, for example:

     <b:b/> elements can be nested arbitrarily deeply when they
     occur inside <a:a1/> elements, but may not be nested when
     they occur in <a:a2/> elements.
--
Cheers,
John