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Re: reification test case

From: Patrick Stickler <patrick.stickler@nokia.com>
Date: Mon, 04 Feb 2002 11:15:15 +0200
To: ext Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
CC: RDF Core <w3c-rdfcore-wg@w3.org>
Message-ID: <B8841DC3.D11D%patrick.stickler@nokia.com>
On 2002-02-04 11:03, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> wrote:

> [sorry for the delay in answer, but I still have to scrape this from the
> rdfcore archive because my mail is still not coming through]
> 
>>> actually I see that already
>>> 
>>> _:s1 <property>      "property" .
>>> 
>>> entails
>>> 
>>> _:s2 <property>      "property" .
>>> 
>>> so I don't see the point of reification
>>> 
>>> --
>>> Jos
>>> 
>>> 
>> 
>> I'm quite curious how you come to this result, since
>> bNodes are distinct and there is no definition by
>> RDF, that I'm aware of, that two bNodes of
>> type rdf:Statement which have an intersection of
>> the same S, P, and O triples are the same "thing".
>> 
>> The two bNodes reify the same triple, but are
>> distinct reifications in their own right. No?
>> Why wouldn't we treat them as distinct resources?
>> 
>> What am I missing here (honestly)?
> 
> Patrick, this is plain MT
> At the end of chapter 2. Simple entailment between RDF graphs.
> you may find
> 
> [[[
> It might be thought that the operation of changing a bound variable
> would be an example of an inference which was valid but not covered
> by the interpolation lemma, e.g. the inference of
> 
> _:x foo baz
> 
> from
> 
> _:y foo baz
> 
> Recall however that by our conventions, these two expressions describe
> identical RDF graphs.
> ]]]
> 
> after all, bNodes are blank (circles with nothing in)
> 
> --
> Jos

Hmmm.... I'm trying to understand this from the viewpoint
of the bNode as denoting "some thing" that has properties.

E.g. if we have

_:B ex:father #Bob .
_:B ex:gender ex:Male .
_:G ex:father #Bob .
_:G ex:gender ex:Female .

does this really entail

_:B ex:gender ex:Female .
_:G ex:gender ex:Male .

I.e. we have two "things", each has the same
father, but they have different genders (i.e
one is a boy/son, the other a girl/daughter).

I don't see this as any different from the
two bNodes of type rdf:Statement which share
the same property values for S, P, and O but
which have other non-shared properties.

If the MT is really saying that _:B is a girl,
then there seems to be a problem with the MT.

Eh?

Patrick

--
               
Patrick Stickler              Phone: +358 50 483 9453
Senior Research Scientist     Fax:   +358 7180 35409
Nokia Research Center         Email: patrick.stickler@nokia.com
Received on Monday, 4 February 2002 04:14:09 EST

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