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Re: Draft RDFCore Comments on Owl Reference

From: Jos De_Roo <jos.deroo@agfa.com>
Date: Sun, 27 Apr 2003 21:59:30 +0200
To: "Brian McBride <bwm" <bwm@hplb.hpl.hp.com>
Cc: RDF Core <w3c-rdfcore-wg@w3.org>, w3c-rdfcore-wg-request@w3.org
Message-ID: <OF2A19496B.0601CA82-ONC1256D15.006DA13E-C1256D15.006DD376@agfa.be>



> DRAFT For Consideration by RDFCore especially the restriction on
annotation
> properties, that if correct as stated, renders some of RDFS not legal OWL
Full.

[...] no major comments

> 6.2 Enumerated datatype
>
> We suggest the following form for writing the syntax of lists with
literal
> values, which we believe is more slightly more readable and better suited
> to longer lists.
>
> [[
> <owl:DatatypeProperty rdf:ID="tennisGameScore">
>    <rdf:range>
>      <owl:oneOf>
>
>        <rdf:List>
>          <rdf:first rdf:datatype="&xsd;integer">0</rdf:first>
>          <rdf:rest rdf:nodeID="l2"/>
>        </rdf:List>
>
>        <rdf:List rdf:nodeID="l2">
>          <rdf:first rdf:datatype="&xsd;integer">15</rdf:first>
>          <rdf:rest rdf:nodeID="l3"/>
>        </rdf:List>
>
>        <rdf:List rdf:nodeID="l3">
>          <rdf:first rdf:datatype="&xsd;integer">30</rdf:first>
>          <rdf:rest rdf:nodeID="l4"/>
>        </rdf:List>
>
>        <rdf:List rdf:nodeID="l4">
>          <rdf:first rdf:datatype="&xsd;integer">30</rdf:first>
>          <rdf:rest rdf:resource="&rdf;nil"/>
>        </rdf:List>
>      </owl:oneOf>
>    </rdf:range>
> </owl:datatypeProperty>
> ]]

did you mean rdfs:range?
it should be </owl:DatatypeProperty>
it still doesn't parse...
  trying Jena-2p1, latest jena2 at
  http://www.w3.org/2002/03owlt/editors-draft/WEB-INF/lib
  cwm v 1.129 ... loosing again...
this is not good; let's try

:tennisGameScore   a owl:DatatypeProperty;
                   rdfs:range [ owl:oneOf (0 15 30)].

and let's see if that together with

:x :tennisGameScore 15.

entails

:x :tennisGameScore [ a [ owl:oneOf (0 15 30)]].

OK, it does


> ---------------------------------------
>
> #owlref-rdfcore-annotation-restriction
>
> 7.1 Annotations
>
> [[
>      * Annotation properties must not be used in property axioms (e.g.,
no
> subproperties are allowed).
> ]]
>
> Since rdfs:domain and rdfs:range are property axioms, this means that we
> can't define a domain and range for an annotation property in Owl.
Further
> rdfs defines rdfs:isDefinedBy to be a subproperty of rdfs:seeAlso.  That
> would mean that not all RDF graphs are legal OWL Full, and that in fact
the
> graph for RDF Schema is not legal OWL Full.
>
> RDFCore objects to such a broad restriction.

agreed and so

rdfs:comment       a owl:AnnotationProperty;
                   rdfs:domain rdfs:Resource;
                   rdfs:range rdfs:Literal.
rdfs:isDefinedBy   rdfs:domain rdfs:Resource;
                   rdfs:range rdfs:Resource;
                   rdfs:subPropertyOf rdfs:seeAlso.
rdfs:label         a owl:AnnotationProperty;
                   rdfs:domain rdfs:Resource;
                   rdfs:range rdfs:Literal.
rdfs:seeAlso       a owl:AnnotationProperty;
                   rdfs:domain rdfs:Resource;
                   rdfs:range rdfs:Resource.

is OWL Full

> ------------------------------------

[...]

> #owlref-rdfcore-transitive-datatype-properties
>
> In 8.1
>
> [[
> Although from the semantics point of view it is not forbidden in OWL Full
> to declare datatype properties to be inverse, transitive, or symmetric,
in
> practice this does not make much sense. (RDF does not allow data values
as
> the subject of a statement).
> ]]
>
> Consider:
>
> eg:lessThan rdf:type   owl:TransitiveProperty .
> eg:lessThan rdf:type   owl:DatatypeProperty .
> eg:size     rdf:type   owl:DatatypeProperty .
> eg:size     rdfs:range xsd:decimal .
>
>
> _:a eg:size _:sa .
> _:b eg:size _:sb .
> _:c eg:size _:sc .
>
> _:sa eg:lessThan _:sb .
> _:sb eg:lessThan _:sc .
>
> entails
>
> _:sa eg:lessThan _:sc .
>
> This is potentially useful and does make sense.

I've tested that as well

:lessThan a owl:TransitiveProperty, owl:DatatypeProperty.
:size a owl:DatatypeProperty; rdfs:range xsd:decimal.
:a :size :sa.
:b :size :sb.
:c :size :sc.
:sa :lessThan :sb.
:sb :lessThan :sc.

entails

:a.:size :lessThan :c.:size.


-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
Received on Sunday, 27 April 2003 16:00:58 EDT

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