Re: Proposed extensions to OWL?

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.

Thanks & Regards,

Monika

Roger L. Costello wrote:

>Hi Folks,
>
>Yesterday I sent out a message asking about technologies to express
>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
>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 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 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 <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 
entity to which it is addressed and may contain confidential and/or 
privileged material. Any review, retransmission, dissemination or other 
use of, or taking of any action in reliance upon this information by 
persons or entities other than the intended recipient is prohibited. If 
you received this in error, please contact the sender and delete the 
material from any computer"