# Re: Proposed extensions to OWL?

From: Monika Solanki <monika@dmu.ac.uk>
Date: Sun, 15 Jun 2003 12:41:03 +0100
Message-ID: <3EEC5B4F.4040500@dmu.ac.uk>
To: "Roger L. Costello" <costello@mitre.org>

```Hi,

I was wondering if it would be an idea to introduce, Arithematic and
Logical operators as relationships between properties? Is some work
going on in this direction?. I know about some work on predicate
calculus that has been done at Yale university. however, I have not come
across anything with respect to Arithematic operators.

-Monika

Roger L. Costello wrote:

>Monika Solanki wrote:
>
>>Hi Roger,
>>
>>I am facing a similar problem to yours. I have a class A, which has
>>two properties P1 and P2. I want to state that P2= P1-1. Incidentally
>>I could not find anyways in OWL to express this. Is there some
>>cnstruct  in OWL to state this?
>>
>
>The problem you state is identical to the problem that I am raising.
>Hopefully with some discussion we can come to a good solution.  /Roger
>
>>Roger L. Costello wrote:
>>
>>>Hi Folks,
>>>mathematical relationships.  Robin Berjon responded with a very
>>>interesting idea.  I would like to get your thoughts on it, and see
>>>if
>>>collectively we can come up with something cool.
>>>First I will show you a slightly modified version of Robin's
>>>proposal,
>>>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>
>>>   <owl:DatatypeProperty rdf:ID="length-cm">
>>>      <rdfs:range rdf:resourse="&xsd;decimal"/>
>>>   </owl:DatatypeProperty>
>>>The proposal is to extend OWL to allow you to assert that these two
>>>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() * 2.54"/>
>>>      <rdfs:range rdf:resourse="&xsd;decimal"/>
>>>   </owl:DatatypeProperty>
>>>   <owl:DatatypeProperty rdf:ID="length-cm">
>>>      <owl:equivalentProperty rdf:resource="#length-in"
>>>                        owl-x:conversionFactor="current() / 2.54"/>
>>>      <rdfs:range rdf:resourse="&xsd;decimal"/>
>>>   </owl:DatatypeProperty>
>>>where:
>>>
>>>  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
>>>said:
>>>"For instance:
>>><foo:PropertyEquivalence from='measure:inch'
>>>                          to='measure:cm'
>>>                          convert='\$in_1 * 2.54'/>
>>><foo:PropertyEquivalence from='measure:cm'
>>>                          to='measure:in'
>>>                          convert='\$in_1 div 2.54'/>
>>>would allow you to declare that the following are equivalent:
>>><geo:Distance>
>>>   <measure:inch>2</measure:inch>
>>></geo:Distance>
>>><geo:Distance>
>>>   <measure:cm>5.08</measure:cm>
>>></geo:Distance>
>>>You could allow for multiple inputs to your binding:
>>><foo:PropertyEquivalence
>>>                  from='size:width/measure:meter<
>>>br>size:length/measure:meter'
>>>                  to='size:surface/measure:squareMeter'
>>>                  convert='\$in_1 * \$in_2'/>
>>>and perhaps equivalentize, depending on whether it makes sense in
>>>that
>>>context:
>>><flat:Bedroom>
>>>   <size:width><measure:meter>4</measure:meter></size:width>
>>>   <size:length><measure:meter>5</measure:meter></size:length>
>>></flat:Bedroom>
>>><flat:Bedroom>
>>>   <size:surface>
>>>     <measure:squareMeter>20</measure:squareMeter>
>>>   </size:surface>
>>></flat:Bedroom>
>>>so that given the first you could still query for flat:Bedrooms that
>>>are larger than 20sqm.
>>>You may need to throw in stuff from EXSLT Math if you want more than
>>>XPath provides."
>>>....
>>>Okay, those are the two ideas thus far.  What do you think?  Feel
>>>free
>>>to say
>>>so. The intent here is to brainstorm.  If these conversion rules are
>>>better stated using another technology (e.g., RuleML) please say so.
>>>/Roger
>>>
>>--
>>
>>>**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
>>>
>>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/
>>
>>>**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
>>>
>>"NOTE: The information transmitted is intended only for the person or
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>>
>

--
>**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
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 <mailto:monika@dmu.ac.uk>
web: http://www.cse.dmu.ac.uk/~monika/
<http://www.cse.dmu.ac.uk/%7Emonika/>
>**<>**<>**<>**<>**<>**<>**<>**<>**<>**<
"NOTE: The information transmitted is intended only for the person or
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