Re: Question about MARCXML to Models transformation

Tom


There is a property restriction on the class Expression:
 
frbrer:C1002 rdfs:subClassOf
 [
 rdf:type owl:Restriction;
 owl:onProperty frbrer:P2002;
 owl:onClass frbrer:C1001;
 owl:qualifiedCardinality "1"^^xsd:nonNegativeInteger
 ].


(English labels: C1002 = "Expression", P2002 = "is realization of", C1001 =
"Work")
 
I think this leads to the second of your interpretations: if an instance of
Expression, then 1 and only 1 instance of Work.
 
There is a similar property restriction on the class Item ("is exemplar of" 1
and only 1 Manifestation). The class Manifestation has a property restriction
("is embodiment of" at least 1 Expression.
 
Cheers
 
Gordon
 
 

On 04 March 2011 at 14:10 Thomas Baker <tbaker@tbaker.de> wrote:

> Gordon,
>
> On Tue, Mar 01, 2011 at 01:53:48PM +0000, Gordon Dunsire wrote:
> > However, you need to think about the implications of using the FRBRer, FRAD
> > and
> > FRSAD models. They have strong ontological constraints; for example, an
> > instance
> > of the class frbrer:Expression requires the existence of an instance of the
> > class frbrer:Work (but not vice-versa). IFLA will publish an OWL ontology
> > for
> > FRBR later this month (March 2011).
>
> A point of clarification...  Do you mean that given an instance
> of the class frbrer:Expression, one has license to _infer_
> the (theoretical) existence of an instance of the class
> frbrer:Work -- even if that instance has not actually been
> explicitly declared?
>
> Or does the model somehow require that for every instance of
> Expression, an instance of Work must be explicitly declared?
>
> Tom
>
> --
> Tom Baker <tbaker@tbaker.de>