Jacek Kopecky
Thu, 02 Sep 2010 03:40:28 -0700
Dear Sergey, a reification doesn't assert the original statement, so #2 doesn't imply #1. If you want to talk about #1, you need #2; but if you want to assert #1, it needs to be explicit in the data. In effect, you want both #1 and #2 together if you want to talk about the original source of the statement.
Here's the relevant excerpt from the RDF primer:
Note that asserting the reification is not the same as asserting the original
statement, and neither implies the other. That is, when someone says that John
said something about the weight of a tent, they are not making a statement
about the weight of a tent themselves, they are making a statement about
something John said. Conversely, when someone describes the weight of a tent,
they are not also making a statement about a statement they made (since they
may have no intention of talking about things called "statements").
Hope it helps,
Jacek
On 1 Sep 2010, at 13:13, Sergey Novikov wrote:
> Hello.
>
> I'm following rdf specification that states that this two approaches must
> lead to the same result with only difference that in second case I can make
> statements about another statement.
>
> #1
> exproducts:item10245 exterms:weight "2.4"^^xsd:decimal .
> #2
> exproducts:triple12345 rdf:type rdf:Statement .
> exproducts:triple12345 rdf:subject exproducts:item10245 .
> exproducts:triple12345 rdf:predicate exterms:weight .
> exproducts:triple12345 rdf:object "2.4"^^xsd:decimal .
>
> but request like
>
> Select * where { ?s exterms:weight ?o. } return nothing.
>
> RDF Primer topic: http://www.w3.org/TR/rdf-primer/#reification
>
> Is there a way to "turn on" this functionality or it is me who is missing
> something(like chose specific inference rules file)?
> Of cause I can make my custom rules - but that is not seems to be right for
> this case.
>
> The reason I'm doing this is because according to my workflow I must track
> original source of some statement. And this standard way would be the best
> solution. Just to make statement "exproducts:triple12345 my:StatementSource
> users:User123.
>
> I'm using owlim-3.3.
> configuration:
>
> owlim:ruleset "owl2-rl-reduced" ;
> owlim:repository-type "weighted-file-repository" ;
> owlim:ftsIndexPolicy "onCommit";
>
> Thank you.
>
> Best regards,
>
> Sergey Novikov
>
> <ATT00001..txt>
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