From: Jeff Heflin (heflin@cs.umd.edu)
Date: 01/30/01
I have made a few comments on Peter's skeleton for the third view of
concrete and abstract domains (they are interspersed with his text).
With these changes, I'd be willing to support this proposal.
"Peter F. Patel-Schneider" wrote:
>
> Here is one *possible* skeleton for the third view. I have not analyzed
> this extensively, so there is the distinct chance of problems herein.
>
> daml:Thing the entire domain
> rdfs:Literal <= daml:Thing the concrete subdomain
> this requires a union type for all
> concrete types
> rdfs:Resource <= daml:Thing the abstract subdomain ?
The RDF Schema Spec says "All things being described by RDF expressions
are called resources, and are considered to be instances of the class
rdfs:Resource." Therefore, I don't think Resource can be a subclass of
daml:Thing. I'd rather see it the otherway around, i.e.,
rdfs:Resource the entire domain
rdfs:Literal <= rdfs:Resource the concrete subdomain
daml:Thing <= rdfs:Resource the abstract subdomain
> rdfs:Class the class of all classes
> note that concrete datatypes are
> now classes (I think)
>
> daml:AbstractClass the class of all abstract classes
> daml:ConcreteClass the class of all concrete classes
This is fine. Note that with my suggestion, it might clarify things to
think of rdfs:Literal as the top (most general) class of
daml:ConcreteClass and daml:Thing as the top class of daml:AbstractClass
(as rdfs:Resource is the top class of rdfs:Class).
> rdf:Property
> rdfs:domain = rdfs:Resource
> rdfs:range = rdfs:Thing
This isn't quite right. When specifying a property, its subject is an
instance of an AbstractClass (not a specific individual), and its object
is an instance of a Class. Thus, this should be:
rdf:Property
rdfs:domain = daml:AbstractClass
rdfs:range = rdfs:Class
> daml:AbstractProperty
> rdfs:range = rdfs:Resource this requires the change to rdfs:range
>
> daml:ConcreteProperty
> rdfs:range = rdfs:Literal this requires the change to rdfs:range
Similar to above, these should be:
daml:AbstractProperty
rdfs:range = rdfs:AbstractClass this requires the change to
rdfs:range
daml:ConcreteProperty
rdfs:range = rdfs:ConcreteClass this requires the change to
rdfs:range
> daml:disjoint these can only involve abstract classes
> daml:unionOf
> daml:disjointUnionOf
> daml:intersectionOf
>
> daml:disjointWith
> rdfs:domain = daml:AbstractClass
> rdfs:range = daml:AbstractClass
>
> daml:complementOf
> rdfs:domain = daml:AbstractClass
> rdfs:range = daml:AbstractClass
>
> daml:Restriction <= daml:AbstractClass
>
> daml:onProperty
> rdfs:domain = daml:Restriction
> rdfs:range = rdfs:Property
>
> daml:toType
> rdfs:domain = daml:Restriction
> rdfs:range = rdfs:Class
>
> daml:hasValue
> rdfs:domain = daml:Restriction
> rdfs:range = daml:Thing
If rdfs:Resource is the set of all values in both the concrete and
abstract domains, then this should be:
daml:hasValue
rdfs:domain = daml:Restriction
rdfs:range = rdfs:Resource
> daml:hasType
> rdfs:domain = daml:Restriction
> rdfs:range = rdfs:Class
>
> daml:hasTypeQ
> rdfs:domain = daml:Restriction
> rdfs:range = rdfs:Class
>
> daml:minCardinality
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
>
> daml:maxCardinality
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
>
> daml:cardinality
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
>
> daml:minCardinalityQ
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
>
> daml:maxCardinalityQ
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
>
> daml:cardinalityQ
> rdfs:domain = daml:Restriction
> rdfs:range = >=0
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