W3C home > Mailing lists > Public > public-rif-wg@w3.org > March 2008

Re: ACTION-420 Review of SW-compatibility

From: Jos de Bruijn <debruijn@inf.unibz.it>
Date: Tue, 11 Mar 2008 09:55:58 +0100
Message-ID: <47D6491E.6070109@inf.unibz.it>
To: axel@polleres.net
CC: RIF <public-rif-wg@w3.org>

>> I just see three options:
>> 1 define compatibility only with respect to standard RDF
>> 2-define compatibility with respect to generalized RDF
>> 3- define compatibility with respect to "semi-generalized" RDF, in 
>> which you would not have literals and blank nodes in property positions
> 
> So: defining compatibility wrt. generalized RDF and then restricting it 
> wrt. standard RDF is not an option?

I don't see any point in doing that.  The definition would be exactly 
the same, save the additional syntactical restriction on RDF graphs.

People want to do interoperation between standardized RDF and RIF (which 
will be the lion share) can simply use the definitions for 
RIF-generalize RDF compatibility.

>> Option 3 does not make any sense to me, since I don't see any argument 
>> for disallowing literals and blank nodes in predicate positions when 
>> generalizing RDF.
>> Option 1 has the potential advantage that it might be easier to 
>> understand, because some people might not grasp the idea of 
>> generalized RDF.
>> Option 2 has the advantage that it can be used with an extended notion 
>> of RDF graphs; it can does accommodate certain possible future 
>> extensions.
>>
>>
>> As I stated earlier, it makes sense to me to consider generalized 
>> graphs, because the syntactical restrictions imposed by RDF on triples 
>> are rather silly. 
> 
> they are not silly implementation wise. eg rdf stores store triples most 
> efficiently using tables per predicates. since predicates are basically 
> the *only* position where you are guaranteed to have only constrants, 
> they are somehow special. blank nodes in pred-positions would mess this 
> up big time. :-)

If you want to store your predicates, you can still assign a name to the 
blank node and use this as the name of your table.

Best, Jos

> 
> axel
> 
> 
> 
>> However, I do not feel that strongly.
>>
>>
>>
>> Best, Jos
>>
>>>
>>> Axel
>>>
>>
> 
> 

-- 
                          debruijn@inf.unibz.it

Jos de Bruijn,        http://www.debruijn.net/
----------------------------------------------
One man that has a mind and knows it can
always beat ten men who haven't and don't.
   -- George Bernard Shaw


Received on Tuesday, 11 March 2008 08:56:19 GMT

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