The query in fig. \ref{347168} with inferencing on and off. Investigation revealed that the empty results when the reasoner is off is likely due to class equivalency axioms (e.g.,  "pvu:inbook sr:equivalentClasses sr:BookChapter" not being interpreted as to allow mapping instances of 'pvu' (Pure-VU) classes to 'sr' (Scientific Research, the main student ontology) classes. As a result, sr:classes ended up with no instances (or a couple of hard-coded example instances) as if Pure-VU dataset was not imported. (Note: These two versions of the query is not demonstrated on Linked Data Reactor interface, as turning off the reasoner of LD-R lead to problems on a more fundamental level (i.e., LD-R not being able to read any data at all). The absence of this situation in Protege [which was set to use Fact++ reasoner] and Stardog's query editor [above] indicates that the reasoning types may be different between these applications, and that some definitions necessary for LD-R's reasoning engine may not be present without reasoning.)