- From: Bijan Parsia <bijan.parsia@manchester.ac.uk>
- Date: Wed, 24 Jun 2015 19:49:08 +0000
- To: Ignazio Palmisano <ipalmisano.mailings@gmail.com>
- CC: Owl Dev <public-owl-dev@w3.org>
On Jun 24, 2015, at 13:34, "Ignazio Palmisano" <ipalmisano.mailings@gmail.com> wrote: [snip] >> Like ic:imports? :-) [1] Or trowl:Nbox? [2] >> >> And these aren't dangerous?? > > Uh, different semantics intended for some reasoners but undetectable to others. Not undetect*able*, just undetected ;) We didn't leave a good mechanism for extensions, so there isn't a lot of choice. > <insert sound of a mechanic who's just been asked exactly how bad the > breakage is/> [3] > > > I'm sure I've heard of the concept somewhere else. Was that Embrace > and Extend? or SQL dialects? If we can activate the community group and document stuff, it could help. Getting standarised on DL safe rules would be a good step. [snip] >> Maybe we could use annotation prop... oh, right. >> >> >> ?? I've no in principle objection to magic annotation properties. > > I tremble in fear. Well, in practice they are generally a bad idea ;) at least for arbitrary extensions. Magic annotation properties for onto clean (for example) seems fine (but onto clean is also largely compatible as an add on). Having a magic annotation namespace that strict tools could know to react against if unknown would help mitigate. > I. > > [1] http://www.virginiaautoservice.com/wp-content/uploads/2015/01/bigstock-Car-Repair-3295842.jpg > >> One convention that might work would be to use a faux property (e.g. >> kludge:isKnownMagicAnnotationProperty) for such mandatory annotation >> properties, and make contradictory positive and negative assertions about >> the property. >> >> Tools that know the right magic can discard these assertions; tools that >> know about the convention can signal a useful error; tools that do not know >> about the convention can detect an inconsistency. >> >> An alternative approach would be to use disjoint metaclasses to force >> inconsistency (might give better error messages / faster failure for EL). >> >> (There are also recommendations like SKOS that use annotation properties, >> instead of data or object properties, for properties that are central to the >> subject area. This is problematic for reasoners using the direct semantics.) >> >> Sorry, I don't know what you want to do. If you want to design a general >> extension mechanism, you can find lts of prior discussion in the owl wg wiki >> and archives. >> >> Cheers, >> Bijan. >
Received on Wednesday, 24 June 2015 19:49:36 UTC