- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Fri, 06 Mar 2009 13:23:06 -0500 (EST)
- To: ivan@w3.org
- Cc: boris.motik@comlab.ox.ac.uk, public-owl-wg@w3.org
Probably OK, but not that useful, so no real reason to add it. peter From: Ivan Herman <ivan@w3.org> Subject: Re: A description of the changes necessary to implement named data ranges Date: Fri, 06 Mar 2009 11:40:21 +0100 > Just to clarify: what about OWL RL? Can I name a specific > DataIntersection (which is allowed there)? If so, there might be effects > on the Profile document, too. > > Ivan > > Boris Motik wrote: >> Hello, >> >> Here is a description of how the named data range extension would work. In >> short, we'd introduce a new type of axioms called DatatypeDefinition. These >> would allow you to define a datatype as having some built-in value. Then, you >> would be able to write something like this: >> >> (1) Declaration( Datatype( a:myDT ) ) >> (2) DatatypeDefinition( a:myDT DatatypeRestriction( xsd:integer ... ) ) >> >> Note that (1) is necessary because without it, axiom (2) alone would invalidate >> the typing constraints (it would use a URI that is not properly typed). These >> axioms would be mapped into RDF into (3) and (4), respectively: >> >> (3) a:myDT rdf:type rdfs:Datatype >> (4) a:myDT a:equivalentClass ... >> >> >> We would call datatypes occurring in such axioms '''defined'''. To obtain a >> logic with favorable computational properties, in OWL 2 DL we'd have the >> following conditions: >> >> - If the axiom closure contains a datatype declaration, then the datatype MUST >> be in the datatype map or the axiom closure MUST contain a datatype definition >> for the datatype. >> >> - A datatype definition axiom MUST NOT define a datatype that is in the datatype >> map. >> >> - Datatype definitions MUST be acyclic. >> >> - Datatype restrictions MUST involve only datatypes from the datatype map - that >> is, the datatypes defined through datatype definition axioms have no facets. >> >> >> >> All these changes would be reflected in the Syntax document. The impact to all >> other documents would be quite small: >> >> - Changes to RDF Mapping are minimal and involve mapping the new axiom (into RDF >> and back); both changes are minimal. >> >> - Changes to Direct Semantics are minimal and involve defining the semantics of >> the new axiom. >> >> - Changes to the XML Syntax are minimal and involve adding a new axiom. >> >> - There are no changes to the RDF-Based Semantics. >> >> Regards, >> >> Boris >> >> > > -- > > Ivan Herman, W3C Semantic Web Activity Lead > Home: http://www.w3.org/People/Ivan/ > mobile: +31-641044153 > PGP Key: http://www.ivan-herman.net/pgpkey.html > FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Friday, 6 March 2009 18:22:54 UTC