Re: RDF* and grouping relation properties

On 21/06/2020 22:01, Patrick J Hayes wrote:
>
>
>> On Jun 21, 2020, at 5:14 AM, thomas lörtsch <tl@rat.io 
>> <mailto:tl@rat.io>> wrote:
>>
>>
>>
>>> On 18. Jun 2020, at 17:44, Tim Finin <finin@umbc.edu 
>>> <mailto:finin@umbc.edu>> wrote:
>>>
>>> While experimenting with RDF* I realized one issue: for some 
>>> relations, we may have several properties that should be treated as 
>>> a group.  For example, the provenance of a relation extracted from 
>>> the text of a web page might include a link to the page and the date 
>>> retrieved.
>>>
>>> Using the following two RDF* expressions merges the four properties 
>>> so that we can no longer determine which :source and :retrieved 
>>> values go together.
>>>
>>> << :man :hasSpouse :woman >>
>>>    :source <http://foo.com/>;
>>>    :retrieved "2020-06-17"^^xsd:date .
>>> << :man :hasSpouse :woman >>
>>>    :source <http://bar.com/>;
>>>    :retrieved "2020-01-01"^^xsd:date .
>>>
>>> Using a traditional RDF reification approach maintains the pairing.
>>>
>>> :man2 :hasSpouse :woman2 .
>>> [ ]  a rdf:Statement ;
>>>     rdf:subject :man2 ;
>>>     rdf:predicate :hasSpouse ;
>>>     rdf:object :woman2 ;
>>>    :source <http://foo.com/> ;
>>>    :retrieved "2020-06-17"^^xsd:date .
>>> [ ] a rdf:Statement ;
>>>    rdf:subject :man2 ;
>>>    rdf:predicate :hasSpouse ;
>>>    rdf:object :woman2 ;
>>>   :source <http://bar.com/>;
>>>   :retrieved "2020-01-01"^^xsd:date .
>>
>> In my understanding of the RDF Standard Reification semantics your 
>> two blank nodes are owl:sameAs as the reification quad refers to the 
>> abstract triple type, not any concrete token.
>
> Correct. But bear in mind that none of the semantic guidance in the 
> RDF specs for reification is normative. RDF reification has /no/ 
> normative semantics.

I'm confused.

Why don't the additional :source, :retrieve triples differentiate the 
blank nodes making them not owl:sameAs?

Received on Monday, 22 June 2020 11:39:51 UTC