Corrections to RDF Query Language Comparison

I recently came upon this dated comparison of features in RDF querying languages. It predates SPARQL and as a result prompted Dan Connoly to attempt to demonstrate how SPARQL fares in this matrix. In reading it, I realized some of the features marked as 'No' under Versa are incorrect. So here is my attempt to demonstrate how (current Versa specification) would implement these requirements:

5 Quantification: Return the persons who are authors of all publications

The section name is misleading as it suggests the use of FOPL semantics to resolve a pattern that can be solved without FOPL semantics:

        'eq(length(difference(all()-dc:creator->*. - dc:creator->*)),0)'

10 Namespace: Return all resources whose namespace starts with "".


14 Entailment: Return all instances of that are members of the class Publication.

The current specification says (about rdf:type entailment):

Returns a list of all resources of a specified type, as defined by RDFS and optionally DAML schema specifications ...

So, the implementation has the option to account for entailment rules (as the 4Suite implementation does):


Chimezie Ogbuji

via Copia