[RDF+OWL] coreifying RDF(S) combination embeddings

I coreified the RDF(S) combination embeddings [1].
For simple and RDF entailment the update is nearly trivial; "a"="b" in
rule heads is replaced with rif:error (a 0-ary predicate), and
consistency checking is done by checking entailment of rif:error.

For RDFS things become a bit more ugly than I had expected.  To
guarantee safety, facts need to be introduced for every IRI and every
literal that is being used.

by the way, I am pretty happy with isLiteralOfType; it makes the
embeddings quite a bit easier :-)

Best, Jos


[1] http://www.w3.org/2005/rules/wiki/SWC#Embedding_RIF-RDF_Combinations

-- 
Jos de Bruijn            debruijn@inf.unibz.it
+390471016224         http://www.debruijn.net/
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