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Re: A problem with OWL Validator

From: Jos De_Roo <jos.deroo@agfa.com>
Date: Sun, 15 Jun 2003 14:28:14 +0200
To: "Monika Solanki <monika" <monika@dmu.ac.uk>
Cc: semanticweb <semanticweb@yahoogroups.com>, www-rdf-interest@w3.org, www-ws@w3.org, www-ws-request@w3.org
Message-ID: <OFB048EB4C.F9642B80-ONC1256D46.0043EFC0-C1256D46.00448223@agfa.be>

Hi Monika, conceptually there should be no problem
to mix RDF instance data and OWL ontologies.
In my experience I even mix it with log: and math:
formulae (using N3) to find proofs etc...

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

                    Monika Solanki                                                                                 
                    <monika@dmu.ac       To:     www-ws@w3.org, www-rdf-interest@w3.org, semanticweb               
                    .uk>                  <semanticweb@yahoogroups.com>                                            
                    Sent by:             cc:                                                                       
                    www-ws-request       Subject:     A problem with OWL Validator                                 
                    12:56 PM                                                                                       


I have an OWL file, in which I have included some instances as well. When I
parse the file without the instances, it does not give me any error,
however when I do it with  instances, it gives me loads of warning like,
Implicit Property, Undefined Resource, Invalid namespace. I fail to
understand if my ontology is wrongly written or is it wrong to include
instances in the same file. Has anyone come across such errors before.

Please Help.



Roger L. Costello wrote:
     Jos De_Roo wrote:
          we tend to use RDF interpretation properties for that
          and math: properties and N3 conversion rules such as eg

          {?X eg:length-in ?Y} => {?X eg:length-cm (?Y 2.54).math:product}.
          {?X eg:length-cm ?Y} => {?X eg:length-in (?Y


     Hi Jos,

     Does this have an XML syntax?  My interest is in how to express the
     mathematical relationships using an XML syntax.  /Roger

                              "Roger L. Costello"
                              <costello@mitre.org>        To:
                              Sent by:                    cc:
          robin.berjon@expway.fr, "Costello,Roger L." <costello@mitre.org>
                              www-rdf-interest-requ       Subject:
          Proposed extensions to OWL?

                              2003-06-14 01:20 PM

          Hi Folks,

          Yesterday I sent out a message asking about technologies to
          mathematical relationships.  Robin Berjon responded with a very
          resting idea.  I would like to get your thoughts on it, and see
          collectively we can come up with something cool.

          First I will show you a slightly modified version of Robin's
          then I will show Robin's original proposal.

          Robin's Idea Slightly Modified

          The idea is to extend OWL and base the solution on xPath.

          Suppose that I would like to state that these two properties are
          equivalent via a conversion factor:

               length-in, length-cm

          i.e., length in inches, and length in centimeters

          The conversion factor is:

              length-in = length-cm / 2.54
              length-cm = length-in * 2.54

          With today's OWL here is how you would define these properties:

             <owl:DatatypeProperty rdf:ID="length-in">
                <rdfs:range rdf:resourse="&xsd;decimal"/>

             <owl:DatatypeProperty rdf:ID="length-cm">
                <rdfs:range rdf:resourse="&xsd;de

          The proposal is to extend OWL to allow you to assert that these
          properties are equivalent by the above conversion factor.  Here's
          how it
          might look:

             <owl:DatatypeProperty rdf:ID="length-in">
                <owl:equivalentProperty rdf:resource="#length-cm"
                                  owl-x:conversionFactor="current() *
                <rdfs:range rdf:resourse="&xsd;decimal"/>

             <owl:DatatypeProperty rdf:ID="length-cm">
                <owl:equivalentProperty rdf:resource="#length-in"
                                  owl-x:conversionFactor="current() /
                <rdfs:range rdf:resourse="&xsd;decimal"/>

             owl-x is an OWL eXtension namespace,
             current() is the xPath function referring to the current node.

          Now let me show you Robin's idea:

          Robin's idea is also
           to base the solution on xPath. Here's what Robin

          "For instance:

          <foo:PropertyEquivalence from='measure:inch'
                                    convert='$in_1 * 2.54'/>

          <foo:PropertyEquivalence from='measure:cm'
                                    convert='$in_1 div 2.54'/>

          would allow you to declare that the following are equivalent:



          You could allow for multiple inputs to your binding:

                            convert='$in_1 * $in_2'/>

          and perhaps equivalentize, dep
          ending on whether it makes sense in that



          so that given the first you could still query for flat:Bedrooms
          are larger than 20sqm.

          You may need to throw in stuff from EXSLT Math if you want more
          XPath provides."


          Okay, those are the two ideas thus far.  What do you think?  Feel
          to add your own ideas.  If this whole approach is bad, feel free
          to say
          so. The intent here is to brainstorm.  If these conversion rules
          better stated using another technology (e.g., RuleML) please say

Monika Solanki
De Montfort University
Software Technology Research Laboratory
Hawthorn building, H00.18
The Gateway.
Leicester LE1 9BH, UK

phone: +44 (0)116 250 6170 intern: 6170
email: monika@dmu.ac.uk
web: http://www.cse.dmu.ac.uk/~monika/
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Received on Sunday, 15 June 2003 08:28:32 UTC

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