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Re: Semantics, Basic, OWL 2 and POWDER

From: Andrea Perego <andrea.perego@uninsubria.it>
Date: Wed, 14 May 2008 12:08:07 +0200
Message-ID: <482ABA07.6080509@uninsubria.it>
To: Public POWDER <public-powderwg@w3.org>

Hi, Stasinos.

>> [snip]
>>
>> The proposal for the POWDER-BASIC schema requires just includeregexp, 
>> i.e., it does not require any constraint on the IRI host. This means 
>> that, if a POWDER-BASIC document is obtained from a POWDER one, the 
>> constraint on the IRI host is kept, since it is in the original POWDER 
>> document. However, if anyone writes directly his/her own POWDER-BASIC 
>> document, we cannot be sure that the constraint on the IRI host will be 
>> kept.
>>
>> So, we have two options:
>>
>> 1. Drop the constraint on the IRI host: in such a case, this won't be 
>> required by POWDER, and POWDER-BASIC will be as proposed.
>>
>> 2. Keep the constraint: in such a case, the POWDER XML schema won't be 
>> changed, but we have to put such constraint in the POWDER-BASIC XML 
>> schema. I see here a possible option: the POWDER-BASIC XML schema 
>> requires one and exactly one instance of <includehosts /> AND 
>> <includeregexp /> in an <iriset />.
> 
> The whole point of POWDER-BASIC is that it knows nothing about
> <includehosts />, so (2) is not possible.
> 
> (1) is possible, but unnecessary. We can keep the POWDER constraint, and
> not worry about POWDER-BASIC (or, for that matter, POWDER-S) authors.
> 
> Implementors of POWDER-BASIC extensions will have to specify their own
> constraints, depending on their domain and target audience.
> 
> So, I suggest:
> 
> 3. Keep the constraint: in such a case, the POWDER XML schema won't be
> changed. Futhermore, not all POWDER-BASE documents can be turned into
> valid POWDER documents. This looks OK, there is no reason to guarantee
> the convertibility in this direction.

I was not proposing to keep the constraint on the IRI host with the 
purpose of converting POWDER-BASIC into POWDER. The problem is, as I 
said, that, if only includeregexp is required, I can write a 
POWDER-BASIC document claiming that "all the resources hosted by any 
host, and having a path starting with /foo, are blue." Should we allow this?

>> [snip]
>>
>> 1. POWDER + extensions -> POWDER ( -> POWDER-BASIC [optional] )
>>
>> 2. POWDER + extensions -------------> POWDER-BASIC
> 
> No, 2 is:
> 
> POWDER-BASIC + extensions -> POWDER-BASIC

Thanks for this correction.

Andrea
Received on Wednesday, 14 May 2008 10:08:49 GMT

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