- From: Jeff Heflin <heflin@cse.lehigh.edu>
- Date: Wed, 29 May 2002 16:04:57 -0400
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
- CC: www-webont-wg@w3.org
Peter,
Thanks for putting this together. This really helps us get a feel for
what OWL is beginning to look like. Because it is easier to focus on
concrete examples, I've commented on the schema-example.text file.
Please see my comments below (prefaced with a "J:"):
<!-- Examples of OWL XML Syntax -->
<owl:ontology xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns"
xmlns:owl="http://www.owl.org/owl">
J: I'd like to see an example of include here, and the use of a QName to
reference a concept from another ontology somewhere.
<!-- Syntax Comments Why
-->
<owl:EquivalentClass owl:name="Student"> <!-- Good -->
J: Is this syntax supposed to be valid RDF? If so, why do you use
owl:name="Student" instead of rdf:ID?
<owl:super owl:resource="Person" /> <!-- OK - resource
questionable -->
<owl:super owl:resource="Thing" /> <!-- OK - resource
questionable -->
<owl:restriction> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:IndividualRestriction owl:property="child"
owl:atmost="1"> <!-- Good -->
<owl:range> <!-- range="Person" ?
-->
<owl:Class owl:ID="Person" /> <!-- ""
SCHEMA -->
</owl:range> <!-- "" -->
</owl:IndividualRestriction> <!-- OK -->
</owl:restriction> <!-- Unnecessary
STRIPING,SCHEMA -->
J: Is the above restriction a qualified number restriction? If so, your
latest feature synopsis says these were supposed to be removed due to a
WG decision.
<owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:IndividualRestriction owl:property="advisor"
owl:atleast="1"> <!-- Good -->
<owl:range> <!-- range="Person" ?
-->
<owl:Class owl:ID="Person" /> <!-- ""
SCHEMA -->
</owl:range> <!-- "" -->
<owl:required> <!-- <required
class="Person" /> ? -->
<owl:Class owl:ID="Person" /> <!-- ""
SCHEMA -->
</owl:required> <!-- "" -->
J: Why both range and required above? Doesn't atLeast=1 and range=Person
mean required=Person?
</owl:IndividualRestriction> <!-- OK -->
</owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
J: What's the difference between wrapping an IndividualRestriction in a
description or restriction? Also see my comment in reply to the abstract
syntax on whether you need both restriction and description here.
<owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:DataRestriction owl:property="studentID"
owl:exactly="1"> <!-- Good -->
<owl:range> <!-- range="xsd:integer"
? -->
<owl:DataType owl:ID="xsd:integer" /> <!-- ""
SCHEMA -->
</owl:range> <!-- "" -->
</owl:DataRestriction> <!-- OK -->
</owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:Or> <!-- Good -->
<owl:class owl:resource="Foo" /> <!-- OK - resource
questionable -->
<owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:IndividualRestriction owl:property="year"
owl:exactly="1"> <!-- Good -->
<owl:range> <!-- OK -->
<owl:OneOf> <!-- Good -->
<owl:member owl:resource="Freshman" /> <!-- OK - resource
questionable -->
<owl:member owl:resource="Sophomore" /> <!-- OK - resource
questionable -->
<owl:member owl:resource="Junior" /> <!-- OK - resource
questionable -->
<owl:member owl:resource="Senior" /> <!-- OK - resource
questionable -->
</owl:OneOf> <!-- OK -->
</owl:range> <!-- OK -->
</owl:IndividualRestriction> <!-- OK -->
</owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
<owl:DataRestriction owl:property="grade"
owl:exactly="1"> <!-- Good -->
<owl:range> <!-- OK -->
<owl:OneOf> <!-- OK -->
<owl:member xsi:type="xsd:integer">1</owl:member>
<owl:member xsi:type="xsd:integer">2</owl:member>
<owl:member xsi:type="xsd:integer">3</owl:member>
<owl:member xsi:type="xsd:integer">4</owl:member>
</owl:OneOf> <!-- OK -->
</owl:range> <!-- OK -->
</owl:DataRestriction> <!-- OK -->
</owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
</owl:Or> <!-- OK -->
</owl:description> <!-- Unnecessary
STRIPING,SCHEMA -->
</owl:EquivalentClass> <!-- OK -->
<owl:IndividualProperty owl:name="foo" owl:inverseOf="oof"
owl:functional="true">
<owl:super owl:resource="bar" />
<owl:range>
<owl:Class owl:ID="Person" />
</owl:range>
<owl:domain>
<owl:And>
J: I assume owl:And takes the place of intersectionOf from the abstract
syntax. I prefer "And." What about using it in the abstract syntax as
well?
<owl:class owl:resource="Person" />
<owl:class owl:resource="Employee" />
</owl:And>
</owl:domain>
</owl:IndividualProperty>
<owl:IndividualProperty owl:name="trans" owl:inverseOf="snrat"
owl:transitive="true">
J: Why name and not ID, above?
<owl:super owl:resource="p2" />
<owl:super owl:resource="p3" />
</owl:IndividualProperty>
<owl:EnumeratedClass owl:name="CSProfessors"> <!-- Good -->
J: Why name and not ID, above?
<owl:member owl:resource="ProfessorFoo" /> <!-- OK - resource
questionable -->
<owl:member owl:resource="ProfessorFoo" /> <!-- OK - resource
questionable -->
</owl:EnumeratedClass> <!-- OK -->
<!-- RDF-compatible XML-Schema compatible -->
<owl:Individual owl:name="John"> <!-- Good -->
J: Why name and not ID?
<owl:type owl:resource="Person" /> <!-- OK - resource
questionable -->
<owl:property> <!-- Unnecessary
STRIPING -->
<owl:IndividualPropertyValue owl:property="child"> <!-- Good -->
<owl:individual owl:resource="Susan" /> <!-- individual="Susan"
? -->
</owl:IndividualPropertyValue> <!-- OK -->
</owl:property> <!-- Unnecessary
STRIPING -->
<owl:property> <!-- Unnecessary
STRIPING -->
<owl:IndividualPropertyValue owl:property="child"> <!-- Good -->
<owl:individual> <!-- Unnecessary
STRIPING -->
<owl:Individual> <!-- OK -->
<owl:type owl:resource="Person" /> <!-- OK - resource
questionable -->
</owl:Individual> <!-- OK -->
</owl:individual> <!-- Unnecessary
STRIPING -->
</owl:IndividualPropertyValue> <!-- OK -->
</owl:property> <!-- Unnecessary
STRIPING -->
</owl:Individual> <!-- OK -->
J: Wow, the above individual syntax sure is ugly. I like either of the
ones below a lot better, although I think going with the last one (RDF
compatible) is probably best for this effort.
<!-- XML-Schema compatible, but not this schema, and not RDF-compatible
<owl:Individual owl:name="John" owl:type="Person">
<owl:property owl:property="child" owl:individual="Susan" />
</owl:Individual>
-->
<!-- regular RDF, not XML-Schema compatible
<Person owl:ID="John">
<child>
<Person owl:ID="Susan" />
</owl:child>
</owl:Person>
-->
</owl:ontology>
J: One final thing, as your comments suggest, the striping really does
seem to get in the way of clean syntax.
Jeff
"Peter F. Patel-Schneider" wrote:
>
> I put together an XML Schema that closely corresponds to the abstract
> syntax in the OWL Feature Specification document. This is my first
> significant XML Schema, so there may be better ways of doing some of the
> things there. Also enclosed is a simple, nonsensical document using the
> Schema.
>
> Comments are welcome.
>
> peter
>
> ------------------------------------------------------------------------
> Name: schema.xsd
> schema.xsd Type: Plain Text (Text/Plain)
> Encoding: 7bit
>
> Name: schema-example.text
> schema-example.text Type: Plain Text (Text/Plain)
> Encoding: 7bit
Received on Wednesday, 29 May 2002 16:05:35 UTC