Re: Conservative Extension of OWL 2

A conservative extension to an ontology is an extension that commits to
holding a referendum on whether a set of axioms is consistent only after an
extended attempt to renegotiate the applicable rules of inference.

Some other views:

Gruninger, M., & Aameri, B. (2014). Preservation of Modules. In *WoMO@*
*FOIS*.
http://ceur-ws.org/Vol-1248/WoMO14-Paper3.pdf

Grüninger, M., Hahmann, T., Hashemi, A., Ong, D., & Ozgovde, A. (2012).
Modular first-order ontologies via repositories. *Applied Ontology*, *7*(2),
169-209.
http://www.cs.toronto.edu/~torsten/publications/MGruninger_AO-12.pdf

Veloso, P. A., & Veloso, S. R. (1991). On conservative and expansive
extensions.*O** que** no** faz** pensar**:** Cadernos** de**
Filosofia*, *4*(87),
106.
http://www.oquenosfazpensar.com/adm/uploads/artigo/on_conservative_and_expansive_extensions/n4paulo.pdf

Incidentally,  Common Logic,  which is first-order (modulo sequences) with
quantification over known predicates, caused problems for definitional
extensions,  if the newly defined predicates are visible to quantifiers in
the ontology being extended.  That this took years to spot shows how tricky
this all gets.

Simon
On Aug 10, 2015 5:53 PM, "Ignazio Palmisano" <ipalmisano.mailings@gmail.com>
wrote:

> On 10 August 2015 at 22:21, Leila Bayoudhi <bayoudhileila@yahoo.fr> wrote:
> > Hi,
> > I have some questions:
> > -What is exactly a " consrvative extension of an ontology"?
>
> In short, A is a conservative extension of B if all entailments of B
> are also entailments for A. However, the concept is much more complex
> than this. You can start with
> http://cgi.csc.liv.ac.uk/~frank/publ/ijcai07.pdf, and move on to the
> large body of literature on the topic.
>
> Approximations of conservative extensions are also an important
> research area. Many modularisation techniques rely on them. See for
> example http://www.cs.man.ac.uk/~sattler/publications/chks07-just.pdf
>
> (These are pointers to some of the oldest literature on the topic.)
>
> > -Does ontology is expected to have conservative extension since it
> relies on
> > logic?
>
> I'm not clear on what you mean here.
>
> > -Does OWL 2 enables this feature?
>
> No. Building conservative extensions is not enabled by OWL 2. It is a
> complex task (undecidable for high expressivity ontologies).
> Approximations, like modules, can be built without OWL 2 (they predate it).
>
> HTH,
> I.
>
> > thx for answering me.
>
>