ISSUE-120: [Editorial] Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility

broken OWL 1 Full semantics

[Editorial] Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility

State:

CLOSED

Product:

Raised by:

Michael Schneider

Opened on:

2008-04-20

Description:

[This issue is primarily meant to inform the WG. I suggest to close the issue as resolved, after the WG has taken note of the problem.]

It has originally been a desired aim to have complete backwards compatibility of OWL 2 Full with OWL 1 Full, where "backwards compatibility" means that every OWL 1 Full entailment is also an OWL 2 Full entailment.

The semantics of OWL 1 Full have turned out to be inconsistent due to bugs in the semantic conditions for unionOf, intersectionOf, and oneOf axioms.

Since OWL Full has a model-theoretic semantics, inconsistency means that for arbitrary RDF graphs G1 and G2 the entailment "G1 |= G2" holds (because G1 cannot be satisfied).

If the mentioned bugs are corrected in order to make OWL 2 Full consistent (which is easy), there will afterwards exist RDF graphs G1 and G2, for which the entailment "G1 |= G2" does /not/ hold anymore.

So, formally, OWL 2 Full will not be backwards compatible with OWL 1 Full. However, it can still be achieved that OWL 2 Full will be backwards compatible with the /corrected/ version of OWL 1 Full.

Related Actions Items:

No related actions

Related emails:

1. implementation of several resolutions in OWL 2 Full Wiki (from schneid@fzi.de on 2008-04-25)
2. RE: Disposition of some recently raised issues (from schneid@fzi.de on 2008-04-23)
3. RE: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from schneid@fzi.de on 2008-04-21)
4. Re: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from jjc@hpl.hp.com on 2008-04-21)
5. RE: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from schneid@fzi.de on 2008-04-21)
6. Re: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from jjc@hpl.hp.com on 2008-04-21)
7. RE: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from schneid@fzi.de on 2008-04-21)
8. Re: ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from jjc@hpl.hp.com on 2008-04-21)
9. ISSUE-120 (broken OWL 1 Full semantics): Fixing the inconsistency of OWL 1 Full will break perfect backwards compatibility (from sysbot+tracker@w3.org on 2008-04-20)

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