Missing language alternatives when SPARQL query depends on owl:sameAs reasoning

[steve....@vanderbilt.edu]

This problem is described in the context of http://baskauf.blogspot.com/2016/02/reasoning-on-real-linked-data-using.html

To replicate it, load these files:

http://rdf.library.vanderbilt.edu/swwg/sww-group.rdf

https://gist.githubusercontent.com/baskaufs/beeaa94606113b970002/raw/df6ec9cbe57290cc2289d2cc37c221e9f494d153/assertions

The RDF in the files contains these triples:

<http://dx.doi.org/10.4242/balisagevol13.anderson01> 
                 dcterms:title "On Teaching XQuery to Digital Humanists".
<http://orcid.org/0000-0003-0328-0792> 
                foaf:made <http://dx.doi.org/10.4242/balisagevol13.anderson01>.
<http://viaf.org/viaf/168432349> skos:prefLabel "Clifford B. Anderson"@en-us,
                                                "Clifford Anderson"@nl-nl.

There is also an owl:sameAs assertion:

<http://orcid.org/0000-0003-0328-0792> 
                 owl:sameAs <http://viaf.org/viaf/168432349>.

In the settings, I have sameAs reasoning set to "ON".  If I ask the simple SPARQL query:

SELECT ?label
WHERE {
  <http://viaf.org/viaf/168432349> skos:prefLabel ?label.
  }

with reasoning turned off, I get the correct answer:

"Clifford B. Anderson"@en-us

"Clifford Anderson"@nl-nl

If I ask the more complex query:

SELECT ?label
WHERE {
  ?pub dcterms:title "On Teaching XQuery to Digital Humanists".
  ?person foaf:made ?pub.
  ?person skos:prefLabel ?label.
  }

with reasoning turned off, I get no results, as I should.  However, when I turn reasoning on, the owl:sameAs assertion should cause a match on ?person, and both language alternatives should show up in the results. However, I only get 

"Clifford B. Anderson"@en-us

and the second alternative is not returned.

[Evren Sirin]

What version of Stardog are you using? I get the expected answers both
with 4.0.5 and 3.1.4.

Best,
Evren

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[steve....@vanderbilt.edu]

I'm using version 4.0.3 .  I've attached a screenshot of the results, with an added SELECT variable showing the value of ?person.  The sameAs URI that Stardog picked to use was http://orcid.org/0000-0003-0328-0792, which was different from the one that was linked to the skos:prefLabel triples: http://viaf.org/viaf/168432349.

I don't know if that matters or not.

[Evren Sirin]

On Fri, Feb 26, 2016 at 8:04 PM, <steve....@vanderbilt.edu> wrote:
> I'm using version 4.0.3 . I've attached a screenshot of the results, with
> an added SELECT variable showing the value of ?person. The sameAs URI that
> Stardog picked to use was http://orcid.org/0000-0003-0328-0792, which was
> different from the one that was linked to the skos:prefLabel triples:
> http://viaf.org/viaf/168432349.
> I don't know if that matters or not.

Turns out it matters and the bug occurs only when the triples are
asserted for the URI that is not being returned. We'll fix this for
the next release.

Best,
Evren