- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Tue, 10 Feb 2009 14:11:20 -0500 (EST)
- To: public-owl-wg@w3.org
I am proposing the following response to LC Comment 43 sections 2, 5, and 6. In the absence of disagreement I suggest that the RDF mapping document be modified as suggested in the response, the modifications be accepted as editorial, and the response sent out. peter Dear Zhe, Thank you for your message http://lists.w3.org/Archives/Public/public-owl-wg/2009Jan/0083.html on the OWL 2 Web Ontology Language last call drafts. Your message contains multiple sections, affecting more than one document, and will thus generate multiple replies. This response is for sections 2, 5, and 6, which affect the mapping from the functional syntax to RDF graphs. ************************ 5. In the RDF mapping document, is it possible to keep OWL 2 vocabulary a bit smaller by replacing owl:minQualifiedCardinality with the existing owl:minCardinality? Same idea applies to owl:qualifiedCardinality, owl:maxQualifiedCardinality. After all, owl:onClass is there to differentiate the qualified vs. non-qualified case. ************************ The problem here has to do with monotonicity of the RDF semantics. Consider a qualified min cardinality translation, i.e., something like MinCardinality(2 ex:p ex:C), which translates into _:x rdf:type owl:Restriction _:x owl:minQualifiedCardinality "2"^^xsd:nonNegativeInteger _:x owl:onProperty ex:p _:x owl:onClass ex:C If this suggestion was made the translation would instead be _:x rdf:type owl:Restriction _:x owl:minCardinality "2"^^xsd:nonNegativeInteger _:x owl:onProperty ex:p _:x owl:onClass ex:C However, this contains the three-triple translation of MinCardinality(2 ex:p), and The RDF semantic will pick this up, and augment the meaning of the above four triples with the meaning for MinCardinality(2 ex:p). For minimum cardinality things are not so bad, because MinCardinality(2 ex:p ex:C) implies MinCardinality(2 ex:p). However for Cardinality and MaxCardinality this is not the case, and an incorrect meaning will be determined. This kind of problem has been known ever since the original Web Ontology Working Group. The RDF mapping document does not contain all the rationale for the various choices in the mapping, so no change is envisioned in response to this part of your comment. ************************ 2. very minor typo RDF mapping document has a typo in Section 2.2. s/auhtor/author/. 6. In Section 2.2 of RDF mapping document, are we missing a translation? It is unclear how the second example in 2.2 is translated into triples. The AnnotationAssertion in Table 1 has three parameters and that example has only two parameters for AnnotationAssertion. ************************ The second example in Section 2.2 is AnnotationAssertion( a:Peter Annotation( Annotation( a:author a:Seth_MacFarlane ) rdfs:label "Peter Griffin" ) ) This is not syntactically correct. The example was not correctly changed from a previous syntax for annotation assertions. The correct example is AnnotationAssertion( Annotation( a:author a:Seth_MacFarlane ) rdfs:label a:Peter "Peter Griffin" ) namely a singly-annotated annotation assertion. Thank you for pointing out this error. You also point out the mis-typing of a:author in the example. The document has been changed to fix these editorial mistakes. The diffs can be found at .................................. Please acknowledge receipt of this email to <mailto:public-owl-comments@w3.org> (replying to this email should suffice). In your acknowledgment please let us know whether or not you are satisfied with the working group's response to your comment. Regards, Peter F. Patel-Schneider on behalf of the W3C OWL Working Group
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