- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Sun, 03 Aug 2003 08:48:15 -0400 (EDT)
- To: www-rdf-comments@w3.org
I believe that there is a problem with the definition of ``allocated to'' in the simple entailment rules. The definition currently (as of the 31 July version) states The terminology 'allocated to' means that the blank node much have been created by an earlier appliation of the specified rules on the same URI reference or literal, or if there is no such blank node then it must be a 'new' node which does not occur in the graph. My reading of this is that the following RDF graph <ex:a> <ex:p> <ex:b> . cannot be expanded to <ex:a> <ex:p> <ex:b> . <ex:a> <ex:p> _:a . <ex:a> <ex:p> _:b . using the simple entailment rules because once there is a blank node created from <ex:b> then all subsequent rule applications must use that blank node for <ex:b>. Also <ex:a> <ex:p> _:a . cannot be expanded to <ex:a> <ex:p> _:a . <ex:a> <ex:p> _:b . because se1 requires that the object of the triple be a URI reference or literal. This means that the simple entailment rules are not a replacement for the instance relationship, which counters the claim in Section 7.1. Nor are the simple entailment rules complete for simple entailment, which, by the way, is not stated in the document. Nor are the simple entailment rules equivalent to the alternative rule formulation in the second-last paragraph of Section 7.1, as this alternative formulation admits the first expansion above. Nor is this alternative rule formulation a replacement for the instance relationship, as it does not admit the second expansion above. Peter F. Patel-Schneider Bell Labs Research Lucent Technologies
Received on Sunday, 3 August 2003 08:48:23 UTC