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Re: RDF-ISSUE-84 (d-entailment-typed-literals): "Bug" in D-entailment with literals in non-canonical form [RDF Semantics]

From: Antoine Zimmermann <antoine.zimmermann@emse.fr>
Date: Fri, 24 Feb 2012 18:32:34 +0100
Message-ID: <4F47C9B2.50406@emse.fr>
To: Pat Hayes <phayes@ihmc.us>
CC: public-rdf-wg@w3.org


Le 24/02/2012 18:03, Pat Hayes a écrit :
> Yes you may be right. Give me a day to check out the details and then
> probably follow your suggestion. I think this happened because in one
> incarnation of the sematnics, 'names' were only UIRrefs. However, as
> a general change, I would like to make all RDF interpretations give a
> meaning to all IRIs, so that there is no need to mention the
> vocabulary V all the time. This will simplify a lot of arcane
> mathematical detail and edge cases, and might fix this one as well.

Yes, that would be a very nice simplification. That would also solve the 
fact that "apparent tautologies" are not entailed by all graphs, like:

{ :s :p :o } does not entail { :x rdf:type rdfs:Resource }

which is weird.


AZ

>
> Pat
>
> On Feb 24, 2012, at 9:52 AM, Antoine Zimmermann wrote:
>
>> I don't read this in the same way.
>>
>> Here is the text:
>>
>> "If D is a datatype map, a D-interpretation of a vocabulary V is
>> any rdfs-interpretation I of V union {aaa:<  aaa, x>  in D for some
>> x } which satisfies the following extra conditions for every pair<
>> aaa, x>  in D:"
>>
>>
>> So the interpretation interprets the things in V (whatever V is)
>> and it interprets the datatype URIs. It does not necessarily
>> interpret all the literals in the lexical space of all datatypes in
>> D.
>>
>> and the condition on literals say (I emphasize *in V*):
>>
>> "if<aaa,x>  is in D then for any typed literal "sss"^^ddd ***in
>> V*** with I(ddd) = x , if sss is in the lexical space of x then
>> IL("sss"^^ddd) = L2V(x)(sss), otherwise IL("sss"^^ddd) is not in
>> LV"
>>
>>
>> My suggestion is to simply say that:
>>
>> "If D is a datatype map, a D-interpretation of a vocabulary V is
>> any rdfs-interpretation I of V union {aaa:<  aaa, x>  in D for some
>> x } union {"lit"^^aaa: lit in LS(d) for some<aaa, d>  in D } which
>> satisfies the following extra conditions for every pair<  aaa, x>
>> in D:"
>>
>> and we add the following condition:
>>
>> "if<aaa,x>  is in D then for any typed literal "sss"^^ddd such that
>> sss in LS(x), IL("sss"^^ddd) = L2V(x)(sss)"
>>
>>
>> That is, we force interpretations to interpret all literals in
>> datatypes of D. It's probably what was initially assumed but it's
>> better to make it explicit.
>>
>>
>>
>> AZ
>>
>>
>> Le 24/02/2012 16:23, Pat Hayes a écrit :
>>>
>>> On Feb 24, 2012, at 12:43 AM, RDF Working Group Issue Tracker
>>> wrote:
>>>
>>>> RDF-ISSUE-84 (d-entailment-typed-literals): "Bug" in
>>>> D-entailment with literals in non-canonical form [RDF
>>>> Semantics]
>>>>
>>>> http://www.w3.org/2011/rdf-wg/track/issues/84
>>>>
>>>> Raised by: Antoine Zimmermann On product: RDF Semantics
>>>>
>>>> With the current spec, we have the following situation for
>>>> D-entailment, when the datatype map contains xsd:decimal (for
>>>> instance):
>>>>
>>>> :foo :bar "2"^^xsd:decimal .
>>>>
>>>> *does not* D-entail:
>>>>
>>>> :foo :bar "2.0"^^xsd:decimal .
>>>>
>>>> This is because an interpretation is defined relatively to a
>>>> vocabulary V, so that only the names in V are interpreted.
>>>
>>> Yes, but the definition of D-entailment requires the
>>> interpretations to interpret the vocabulary of literals which are
>>> meaningful under the datatype mappings in question. See
>>> http://www.w3.org/TR/rdf-mt/#defDinterp
>>>
>>>
>>>> If a triple contains a name that is not present in V, then the
>>>> triple is necessarily unsatisfied.  This is made very explicit
>>>> in the RDF Semantics document:
>>>>
>>>> "If the vocabulary of an RDF graph contains names that are not
>>>> in the vocabulary of an interpretation I - that is, if I simply
>>>> does not give a semantic value to some name that is used in the
>>>> graph - then these truth-conditions will always yield the value
>>>> false for some triple in the graph, and hence for the graph
>>>> itself."
>>>>
>>>> Since "2"^^xsd:decimal and "2.0"^^xsd:decimal are two different
>>>> names (although denoting the same thing), the first triple can
>>>> be satisfied by a D-interpretation that does not interpret
>>>> "2.0"^^xsd:decimal,
>>>
>>> No, because this would not be a D-interpretation. It is not
>>> defined on the required vocabulary.
>>>
>>> Pat
>>>
>>>> thus the second triple does not follow from the first one.
>>>
>>>>
>>>> This is probably not in line with how implementations work and
>>>> the problem seem to be present in OWL 2 RDF-based semantics as
>>>> well.
>>>>
>>>>
>>>>
>>>>
>>>
>>> ------------------------------------------------------------ IHMC
>>> (850)434 8903 or (650)494 3973 40 South Alcaniz St.
>>> (850)202 4416   office Pensacola
>>> (850)202 4440   fax FL 32502
>>> (850)291 0667   mobile phayesAT-SIGNihmc.us
>>> http://www.ihmc.us/users/phayes
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> -- Antoine Zimmermann ISCOD / LSTI - Institut Henri Fayol École
>> Nationale Supérieure des Mines de Saint-Étienne 158 cours Fauriel
>> 42023 Saint-Étienne Cedex 2 France Tél:+33(0)4 77 42 83 36
>> Fax:+33(0)4 77 42 66 66 http://zimmer.aprilfoolsreview.com/
>>
>>
>
> ------------------------------------------------------------ IHMC
> (850)434 8903 or (650)494 3973 40 South Alcaniz St.
> (850)202 4416   office Pensacola                            (850)202
> 4440   fax FL 32502                              (850)291 0667
> mobile phayesAT-SIGNihmc.us       http://www.ihmc.us/users/phayes
>
>
>
>
>
>

-- 
Antoine Zimmermann
ISCOD / LSTI - Institut Henri Fayol
École Nationale Supérieure des Mines de Saint-Étienne
158 cours Fauriel
42023 Saint-Étienne Cedex 2
France
Tél:+33(0)4 77 42 83 36
Fax:+33(0)4 77 42 66 66
http://zimmer.aprilfoolsreview.com/
Received on Friday, 24 February 2012 17:33:02 UTC

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