- From: pat hayes <phayes@ai.uwf.edu>
- Date: Sun, 1 Jun 2003 19:59:12 -0500
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- Cc: www-rdf-comments@w3.org
>It occurs to me that all the closures are incomplete. > >For example, > > ex:a ex:b ex:c . > ex:d ex:e ex:c . > >entails > > ex:a ex:b _:x . > ex:d ex:e _:x . > >but that this cannot be derived in any of the closure rule sets. Yes, you are right; these rules need to be stated as operations on subgraphs, following the wording of the instance lemma. Or else the notion of 'new' needs to be re-defined, but that would be ugly. Sigh. If only we actually had quantifiers in the syntax. Maybe it was a mistake to try to keep these rules as simple as possible. I will fix this in the next day or so, not sure yet exactly in which way. > >This means that the characterisation of the instance lemma by rules se1 and >se2 is incorrect. > > >Also, as the canonical form of an XML document is some sort of string, That is unfortunately a controversial claim. On some views of the matter, XML documents and strings are distinct classes. Therefore, the MT deliberately allows the possibility that XML documents and the character strings of plain literals can be distinct, so the following entailment is not considered to be valid without some other antecedents. In a word: plain literals and XML literals might be disjoint sets in some interpretations. I ought to put this into an explicit comment, however, for clarification. Obviously, the whole XML literal stuff in the MT needs to be re-done: I am awaiting confirmation from Jeremy that I have it right. Pat > > ex:a ex:b "2"^^rdf:XMLLiteral > >entails > > ex:a ex:b "...." > >where .... is the string that is the canonical form of "2". This is not >however implied by the RDF closure rules. > >peter -- --------------------------------------------------------------------- IHMC (850)434 8903 or (650)494 3973 home 40 South Alcaniz St. (850)202 4416 office Pensacola (850)202 4440 fax FL 32501 (850)291 0667 cell phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes s.pam@ai.uwf.edu for spam
Received on Sunday, 1 June 2003 20:59:12 UTC