- From: Ian Horrocks <Ian.Horrocks@comlab.ox.ac.uk>
- Date: Sun, 4 Nov 2007 19:37:29 +0000
- To: Jeremy Carroll <jjc@hpl.hp.com>
- Cc: Alan Ruttenberg <alanruttenberg@gmail.com>, Michael Schneider <schneid@fzi.de>, public-owl-wg@w3.org
It still isn't clear to me why this is perceived to be a problem, much less if/why there is an *actual* problem. W.r.t. the perception, Alan has explained that punning involves no change to the status of uris, just a pragmatically motivated weakening of the semantics in the DL case and a consequent loss of entailments. I would like to understand better if/why this doesn't address the perception issue. W.r.t. actual problems, I seem to recall someone (Jeremy?) saying that they believed that punning would be problematical from the point of view of the RDF mapping and/or Full semantics, but I don't recall any details being provided. I would also like to know if there is any more information on the (non-) existence of such problems. Ian On 2 Nov 2007, at 16:36, Jeremy Carroll wrote: > > Alan Ruttenberg wrote: >> Ah well, since I am cited I will reply :) >> (I guess I should say "chair hat off") > > (while I raise a couple of points that could be viewed as > procedural rather than substantive, I prefer you to keep your chair > hat off while we have a discussion - as a complete aside, I have > found my own preference for hat-wearing to have resulted in a > rather negative reception in a variety of places). > >> To summarize, I think that Michael accurately calculates the >> entailments, that these are no new surprise, and that they are a >> necessary consequence of exactly the articulated trade off. In >> summary, I don't see anything new in this analysis. > > I am glad we agree on the facts. I don't believe these issues are > stated with as much clarity in the member submission docs, or > elsewhere in the WG archive, hence my sense of 'newness'. I don't > know how new these issues are to the WG as a whole, but I suspect > most participants are not up to speed on all logically consequences > (and non-consequences) of the member submission documents. > > >> That the current proposal does not satisfy all use cases is not >> surprising. The alternative (no alternative provided) provides >> fewer. I'd urge that in order to move the conversation forward, >> that some concrete alternative proposals be put forward - these >> proposals should at least offer increased functionality in the >> direction desired, should not require new research, as that would >> be outside the mandate of the charter, and provide for sound, >> complete, and decidable reasoning, to provide for the user >> community that depends on these aspects of OWL DL. > > By default, in a WG trying to provide a relatively small revision > on an established specification, the alternative to making a change > is to make no change. > > This is HP's preferred option here: i.e. no change from OWL 1.0: > punning prohibited in OWL DL (at least in the RDF form); when a uri > is used, this takes you into OWL Full, and each URI denotes one thing. > > I point to charter text in favour of this position: > [[ > For each new feature, if there is doubt or a perceived problem with > respect to this issue, the guideline should be to not include the > feature > ]] > and > [[ > The existing compatibility between OWL DL and OWL Full should be > preserved > ]] > > both of which seem to me to be directly applicable to punning, and > to argue in favour of the HP preference. > > Jeremy > > > > > >
Received on Sunday, 4 November 2007 19:38:08 UTC