- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Wed, 13 Nov 2002 09:56:55 -0500
- To: pat hayes <phayes@ai.uwf.edu>, Jeff Heflin <heflin@cse.lehigh.edu>
- Cc: www-webont-wg@w3.org
Here's another one for you guys - really happened - I have two students who wanted their ontologies linked - no changes involved but: A publishes P importing Q B publishes Q importing P If the WG decides to go with one of these import closures things (and Pat's examples below show yet more reasons I worry if we've got it right) we need to make sure we handle cycles in some correct way. -JH At 9:46 AM -0500 11/13/02, pat hayes wrote: >Jeff, your email got me thinking about the intricacies which arise >when thinking about imports in the context of a changing world. Here >are few more example scenarios. In each case A, B, C etc are people, >P, Q, R, etc are chunks of OWL in documents. 'changes' means >altering the RDF at a given URL. > >1. >A publishes P >B publishes Q importing P >A changes P (to P') >C reads Q and imports P' > >Now, has C got it right, or not? Or should C have imported P (how?) >Or should B have tracked A's changes (how?) > >2. >A publishes P >B publishes Q >C publishes R importing Q >B changes Q to Q' importing P >D reads R > >Has D got it right? This is really a special case of the first one, >but since the change involves an imports, the effect is magnified, >as it were. Obviously, the change could be arbitrarily far along an >imports-reference chain. > >3. >A publishes P >B publishes Q importing P >A's server crashes >C reads Q , concludes that the imports P is empty, archives the result >A's server comes back online > >Now has C got it right? Or should C have refused to archive an >empty-due-to-404 imports statement? > >Pat > >-- >--------------------------------------------------------------------- >IHMC (850)434 8903 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 -- Professor James Hendler hendler@cs.umd.edu Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Wednesday, 13 November 2002 09:57:02 UTC