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dissatisfaction with the entailment rules development

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Sun, 03 Aug 2003 09:07:24 -0400 (EDT)
Message-Id: <20030803.090724.07263263.pfps@research.bell-labs.com>
To: www-rdf-comments@w3.org


I am deeply dissatisfied with the way the various entailment rules are
specified in the RDF Semantics document (currently the version of 31 July).
I had hoped that the entailment rules would finally end up as complete
syntactic characterizations of entailment.  This would result in lemmas
somewhat along the following lines:

RDF(S) entailment lemma:  S rdf(s)-entails E if and only if there is a
graph that can be derived from S plus the RDF (and RDFS) axiomatic triples
by the appliation of the simple entailment rules and RDF entailment rules
(and RDFS entailment rules) which is a supergraph of E.

Instead the entailment lemmas are incomplete in a disturbing way.  The RDF
entailment lemma defers to simple entailment, which makes it an incomplete
characterization of rdf-entailment.  It would be much better to remove this
incompleteness. 

The RDFS entailment lemma also depends on simple entailment, but also has a
condition that S be rdfs-consistent.  This detracts considerably from the
utility of the RDFS entailment rules.


Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies
Received on Sunday, 3 August 2003 09:29:42 GMT

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