W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > January to March 2011

Comments on Entailment Regimes from Zhe Wu

From: Matthew Perry <matthew.perry@oracle.com>
Date: Tue, 08 Feb 2011 11:33:34 -0500
Message-ID: <4D51705E.7000904@oracle.com>
To: W3C SPARQL Working Group <public-rdf-dawg@w3.org>
CC: "Zhe (Alan) Wu" <Alan.Wu@oracle.com>
Hi,

Here are some comments from Zhe Wu.

- Matt

-------------------------------------------------------------------------------
Some comments I have so far for the entailment regimes doc.

Overall it is very well written.

- fn: is not referenced at all. We can get rid of it.

- in Section 1.3, ".... and is E-equivalent to AG"   We probably want to define E as an entailment regime.
   Right now, it seems to come from nowhere.

- in the paragraph before 2.3, sentence "Under the modified condition not even rdf:_1 would be a solution and even the BGP ex:a  ex:b ?x . would have an empty solution" is a bit tricky to read (with the dot in the middle of the sentence).
==>
"Under the modified condition, rdf:_1 would not be a solution. Further, BGP ex:a ex:b ?x would have no solution at all."

- In the first table in Section 3
   ... sk(P(BGP)) are ground and RDF entailed by sk(SG)
==>
   ... sk(P(BGP)) are ground and RDFS entailed by sk(SG)


- I am a bit confused about if a SPARQL query should return a blank node (skolemized).
   In 2.1, the document says "Clearly, the Skolemized blank nodes should not occur in query results."
   However, in the SELECT ... COUNT(?author) example in 3.2, we are actually counting them.

- The canonicalization related discussion in 4.1 is a bit odd. Basically
   different vendors can return different answers. What is the problem of enforcing a canonicalization?
   Otherwise, we will get different number of results, different counting, .... Not too good for interoperability.

I have gone through the RL part as well. Seems fine.

I haven't looked carefully into OWL 2 RDF-based semantics entailment.
Received on Tuesday, 8 February 2011 16:34:19 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 16:15:45 GMT