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Re: Draft other comments on OWL reference

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Mon, 28 Apr 2003 19:24:22 +0300
To: w3c-rdfcore-wg@w3.org
Message-Id: <200304281924.22202.jjc@hpl.hp.com>

Resend - this seemed to have got lost.

On Sunday 27 Apr 2003 9:52 pm, Jeremy Carroll wrote:
> One point for WG interest ...
>
> I think the following should be a WG comment:
> *******************
> 6.1 Datatypes
> [[
> A typed literal needs to have an XML attribute rdf:datatype ...
> ]]
>
> Its not the literal that has an XML attribute - that is the way it is
> written in rdf/xml.
>
> [[
> In RDF/XML, the type of a literal is specified by an "rdf:datatype"
> attribute. ]]
>
> Similarly:
>
> [[
> When using datatypes, please note that even if the range of a property is
> declared to be of a certain datatype, RDF still requires a rdf:datatype
> attribute in a statement about this property, otherwise it is treated as a
> plain literal.
> ]]
>
> [[
> When using datatypes, please note that even if a property is defined to
> have a range of a certain datatype, RDF/XML still requires that the
> datatype be specified each time the property is used.
> ]]
> ************************
> =========
>
> Other points ...
>
> Noting this was only a FYI, and answering the comment, with the hope that
> this will inform a more pertinent question ...
>
>
> [[[
> 3.1.1
>
> Is there a restriction that there may be only one enumeration for a class
> description?
>
> What happens with:
>
> <owl:Class rdf:ID="c">
>    <owl:oneOf rdf:parseType="Collection">
>      <owl:Thing rdf:about="#a1"/>
>      <owl:Thing rdf:about="#a2"/>
>    </...
> </...
> <owl:Class rdf:about="#c">
>    <owl:oneOf rdf:parseType="Collection">
>      <owl:Thing rdf:about="#b1"/>
>      <owl:Thing rdf:about="#b2"/>
>      <owl:Thing rdf:about="#b3"/>
>    </...
> </...
> ]]
>
> 1) named classes can have any number of descriptions. In which case this is
> consistent if and only if there is an interpretation which simultaneously
> satisifies all of the descriptions.
>
> 2) The first description can only be consistent when #c has one or two
> elements (#a1 and #a2 might be the same)
>
> 3) The second description can only be consistent when #c has one two or
> three elements.
>
> 4) together we see that at least one of the following must be true
>
> :b1 owl:sameIndividualAs :b2
> :b1 owl:sameIndividualAs :b3
> :b2 owl:sameIndividualAs :b3
>
> moreover at least one of
>
> :b1 owl:sameIndividualAs :a1
> :b1 owl:sameIndividualAs :a2
>
> is true. etc. etc.
>
> I have not read the reference text, ....
>
> Later you use "compliment" rather than "complement". Two very different
> words.
>
> bwm:
> > Given that OWL DL requires a separation between object properties and
> > data valued properties, please confirm that OWL DL supports owl:hasValue.
> >  I suggest that since this caused me to pause, that the note be extended
> > to specifically state that OWL DL does support it, perhaps because, as a
> > built in property, it is exempt from the restriction.
>
> rdf:first, and annotation properties are also exempt. I can't think of any
> others, but there might be one or two.
>
>
> Jeremy
Received on Monday, 28 April 2003 13:24:33 EDT

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