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Re: fixed GRDDL formal rules...

From: Dan Connolly <connolly@w3.org>
Date: Tue, 7 Nov 2006 12:38:27 -0600
Message-Id: <ac500051549eb526f8f98662b3ff0e5e@w3.org>
Cc: GRDDL Working Group <public-grddl-wg@w3.org>
To: Murray Maloney <murray@muzmo.com>

On Nov 7, 2006, at 11:00 AM, Murray Maloney wrote:
> At 12:36 AM 11/7/2006 -0600, Dan Connolly wrote:
>> > >[[
>> > >If an information resource IR has an XML representation whose root
>> > >element has a namespace name NS and for any TX, the resource 
>> identified
>> > >by NS has a GRDDL result that is the merge of { ?NSDOC
>> > ><http://www.w3.org/2003/g/data-view#namespaceTransformation> ?TX } 
>> with
>> > >any other RDF graphs, then TX is a GRDDL transformation of IR
>> > >]]
>> > >  http://www.w3.org/2004/01/rdxh/spec#ns-bind
>> > >  1.150  2006/11/05 08:56:53
>
> Maybe it's just me, in which case I'll gladly step aside and let others
> do the heavy lifting, but I still can't follow the statement above.

In my most recent elaboration of these rules (1.155), I only did 
section 2.
Perhaps you could back up and see if the rules in section 2 make
sense with the example woven in?

>
> 1) If an information resource IR has an XML representation whose root 
> element
>     has a namespace name NS
>
> I get this. We start with an XML document with a namespace NS declared 
> on it.
>
> 2) and for any TX,
>
> Huh? Why "for any TX"? What does this mean?

It means "for any value of the variable TX". I can't think of how to 
explain,
except perhaps by weaving an example around the rule.

>  Aren't there a limited number
> of TXs that pertain to that NS?

Well, yes, the values of TX are further constrained in other
parts of the rule...

>  I don't understand this part.
>
> 3) the resource identified by NS has a GRDDL result
>
> Um. An NS has a GRDDL result IFF a namespaceTransformation has been 
> nominated
> and that TX returns an RDF result.

No, not IFF. There are several of ways for an NS to have a GRDDL result.

> 4) that is the merge of
> { ?NSDOC <http://www.w3.org/2003/g/data-view#namespaceTransformation> 
> ?TX }
>
> That is the merge of its namespace Transformation
>
> 5) with any other RDF graphs,
>
> So the NS had a TX and its graph is a merge with some other RDF graph

All that merge stuff is just saying that the result of NS we're talking 
about can have
other stuff in it besides the one namespaceTransformation triple. Maybe 
it would
be more clear if I phrased it in terms of "subgraph" rather than 
"merge". I'll have
to think about that.

> 6) then TX is a GRDDL transformation of IR
>
> I am lost again. How did this follow?

It doesn't follow from anything; it is the definition/axiom from which 
other things follow.

> I am not trying to be deliberately obtuse. I simply don't follow.

I'm sure you're representing lots of other folks who are quietly not 
following.

If rev 1.155 of section 2 is clear, I can try something like that in 
section 3.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Tuesday, 7 November 2006 18:38:22 GMT

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