- From: Cresswell, Stephen <stephen.cresswell@tso.co.uk>
- Date: Fri, 8 Jul 2011 16:18:19 +0100
- To: "Khalid Belhajjame" <Khalid.Belhajjame@cs.man.ac.uk>, <public-prov-wg@w3.org>
- Message-ID: <F22D0BFCDD4DDC44B92C4E24D751CB930D9643@W3EXC017023.theso.co.uk>
I have another issue with the current definition of "IPV of". As it currently stands, I believe that it does not exclude the possibility that two bobs may be mutually "IVP of" each other - i.e. you could have bobs A, B such that (B IVPof A) & (A IVPof B), and this is surely not intended. This could arise if, for bobs A, B : - A and B both represent the same entity - A and B share some immutable properties, and they have corresponding values. - B has some immutable properties which correspond to mutable properties of A - A has some immutable properties which correspond to mutable properties of B Possibly the asserter-defined test (included in "IPV of" definition) that real world states modelled by A and B are "consistent" may disallow "IPV of" in this situation. However, unless that is guaranteed, I think that the definition of "B IPV of A" (if it is still to have a definition) should additionally require that: "A has no immutable properties which correspond to mutable properties of B" Stephen -----Original Message----- From: public-prov-wg-request@w3.org on behalf of Khalid Belhajjame Sent: Fri 08/07/2011 16:01 To: public-prov-wg@w3.org Subject: Regarding the definition of IVP OF During the F2F meeting, there was a discussion in the second day regarding "IVP of". The definition that was suggested during the F2F can be found in [1]. In my opinion, the definition of "IVP of" should be simplified. Specifically, I would prefer a definition that states that "IVP of" is an asserted relationship between two entity states. I list in what follows the reasons: (i) In the definition of "IVP of" [1], the conditions on the properties of the two entity states A and B (i.e., that the properties the entity states share must have corresponding values, and that some mutable properties of A correspond to some immutable properties of B), are not enough in order to infer that B is an IVP of A. This is because there is a third condition that is not included, because it is hard to formally specify, viz. A and B are consistent. (ii) A consequence of (i), is that we will not be able to automatically infer that an entity state B is an IVP of another entity state B. All we can safely do, is identify cases in which an entity state B cannot be an IVP of another entity state of A. (iii) Even if we find a means for formally specifying that two entity states A and B are consistent, e.g., using assertions, it will be difficult to use the definition of IVP of to make inference. This is because the definition of IVP of requires correspondences between the properties of two entity states to be specified. These correspondences can be complex many-to-many mappings that may turn out to be hard to encode using existing semantic web technologies. Thanks, khalid ________________________________________________________________________ This e-mail has been scanned for all viruses by Star. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________ *********************************************************************************************** This email, including any attachment, is confidential and may be legally privileged. If you are not the intended recipient or if you have received this email in error, please inform the sender immediately by reply and delete all copies from your system. Do not retain, copy, disclose, distribute or otherwise use any of its contents. Whilst we have taken reasonable precautions to ensure that this email has been swept for computer viruses, we cannot guarantee that this email does not contain such material and we therefore advise you to carry out your own virus checks. We do not accept liability for any damage or losses sustained as a result of such material. Please note that incoming and outgoing email communications passing through our IT systems may be monitored and/or intercepted by us solely to determine whether the content is business related and compliant with company standards. *********************************************************************************************** The Stationery Office Limited is registered in England No. 3049649 at 10 Eastbourne Terrace, London, W2 6LG
Received on Friday, 8 July 2011 15:23:36 UTC