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RE: DAML+OIL (March 2001) released

From: Hart, Lewis <lhart@grci.com>
Date: Tue, 10 Apr 2001 11:11:28 -0400
Message-ID: <09A65DF294F8D311AAB000105A02DBAF026E5CFF@thumper.va.grci.com>
To: www-rdf-logic@w3.org
I have some rather pedestrian, non-theoretical questions about the latest
DAML+OIL specification. The specification page directs comments to this
list, but the typical list topics have been far removed from these types of
issues. But if this is not the forum to address them, then where should they
be addressed? 

Some examples of questions I have are: 

Consider this partial definition from the latest spec...

<rdf:Property rdf:ID="unionOf">
  ... omitted ...
  <rdfs:domain rdf:resource="#Class"/>
  <rdfs:range rdf:resource="#List"/>
</rdf:Property>

Why is it not defined like this:

<ObjectProperty rdf:ID="unionOf">
  ... omitted ...
  <domain rdf:resource="#Class"/>
  <range rdf:resource="#List"/>
</ObjectProperty>

Specifically, 

1. The semantics of rdfs:domain, which are "believed to be flawed" [1],  are
different that the semantics of daml:domain. So, why is rdfs:domain used?
Would it not, in general,  be preferred to use daml:domain in the DAML+OIL
specification? 

2. The property daml:unionOf is of type rdf:Property, but has domain and
range of daml:Class and daml:List. How should a RDF (but not DAML) aware
agent deal with that? Or, stated another way, if we are trying to allow some
usability of DAML by RDF/RDFS only applications, this doesn't seem to
support that.

3. This is a property which relates objects to other objects, wouldn't the
daml:unionOf be better defined as a daml:ObjectProperty?

Thanks. - Lewis

[1] http://www.daml.org/2001/03/reference.html#domain-def

___________________________________________
Lewis L Hart 
GRC International                           lhart@grci.com
1900 Gallows Rd.                  Voice (703)506-5938
Vienna, Va 22182                    Fax (703)556-4261
Received on Tuesday, 10 April 2001 11:11:37 GMT

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