[seek-kr-sms] property restrictions in growl

[Shawn Bowers]

Sorry, I was being a bit vague.

What Rich says below is what I was trying to say.  You have to say (not 
necessarily with domain and range)

<owl:ObjectProperty rdf:ID="myprop"/>

before you can use "myprop" to define a class (e.g., an onProperty 
restriction).

The "global" constraints on a property include functional, symmetric, 
transitive, and so on.


shawn


Rich Williams wrote:
>>
>>Do you mean that all syntax checkers you have used would require user to
>>say "property P has domain C1 and range C2) before user  can  say
>>something like
>>(forall P C3)  or (>4 P C4) (????)
>>
> 
> 
> As far as I can tell, both Jena and OWLAPI require that a property be
> declared before it is used.  So for example
> 
>   <owl:ObjectProperty rdf:ID="objProp"/>
>   <owl:Class rdf:ID="Test1">
>     <rdfs:subClassOf>
>       <owl:Restriction>
>         <owl:onProperty>
>           <owl:ObjectProperty rdf:about="#objProp"/>
>         </owl:onProperty>
>         <owl:minCardinality
> rdf:datatype="http://www.w3.org/2001/XMLSchema#int"
>         >2</owl:minCardinality>
>       </owl:Restriction>
>     </rdfs:subClassOf>
>   </owl:Class>
> 
> is fine in both, but remove the first line and both complain.  So no need
> for a domain and range specification, just a declaration of the property's
> existence (which of course in OWL has an implicit range, since object and
> data properties are differentiated).
> 
> Now for my 2-cents worth on this.  I think that when creating a property
> restriction, the user interface should have a text box that incrementally
> matches on the current (object or data) property names.  If the user types
> in a non-existent property name, the editor should create the property, so
> that it is in the list of known property names the next time a restriction
> is created.  The owl file needs to be saved with a property declaration in
> it, otherwise no known tool will be able to read it in.
> 
> 
>>I understand what are restrictions defined for a class. What do you mean
>>by restriction defined at property level?
>>
> 
> 
> I think global restrictions like functional property?
> 
> 
>>Thanks,
>>serguei
>>
>>Shawn
>>
>>
>>Serguei Krivov wrote:
>>
>>>Hi All,
>>>
>>>We have been working hard on first alpha release of growl. Yet we have
>>
>>>got a couple of important issues which probably should be resolved
>>>beforehand. A long discussion between me and Rich have not brought us
>>
>>to
>>
>>>a clear consensus, so the feedback from the group is wanted at least
>>
>>for
>>
>>>the most controversial issues.  Here is one:
>>>
>>>
>>>
>>>Issue #1  Should we allow user to define property restrictions without
>>
>>>defining  explicitly the repective property? Or should we demand that
>>>user alwase define a property with domain and range and only then get
>>>permision to define (any) restriction on this property.
>>>
>>>
>>>
>>>We are not sure what is legal in owl, specifically in owl-dl, but we
>>>have different intuitions about it. On one hand when reading a
>>
>>property
>>
>>> restriction with no explicit property definition owlapi   complains
>>> that it is not an owl-dl construct. Also just to exclude the
>>>possibility of typos while defining restriction it would be
>>
>>advantageus
>>
>>>to have combo boxes that strictly confine  the names for restriction
>>
>>to
>>
>>>link them to the properties that have been already defined.
>>>
>>>
>>>
>>>On the other hand, we know it that definition of domains and ranges is
>>
>>>not realy requred for tableaux algorithms to reason. Moreower -
>>
>>semantic
>>
>>>of  domains and ranges in owl-dl is defined   via property
>>
>>restrictions
>>
>>>which are  the elementary constructs in DL. Therefore the complains in
>>
>>>owlapi about non-dl construct  is weared. It may be related to the
>>
>>fact
>>
>>>that  from owl syntax it does not follow if a restriction pertained to
>>
>>>data property or object property. For example here is the code:
>>>
>>>
>>>
>>><owl:Class rdf:about="http://a.com/ontology#Object1">
>>>
>>>  <rdfs:subClassOf>
>>>
>>>  <owl:Restriction>
>>>
>>>    <owl:onProperty rdf:resource="http://a.com/ontology#Relation1" />
>>>
>>>        <owl:minCardinality
>>>rdf:datatype="http://www.w3.org/2001/XMLSchema#int"
>>>
>>>        >2</owl:minCardinality>
>>>
>>>  </owl:Restriction>
>>>
>>>  </rdfs:subClassOf>
>>>
>>></owl:Class>
>>>
>>>
>>>
>>>Is Relation1 an object property or a data property? From owl syntax it
>>
>>>does not follow and may be this is a reason for the complain. This
>>>uncertainty as we see it here may be a problem of owl design , but it
>>
>>is
>>
>>>not problem of growl, since growl has different node types for object
>>>property restrictions and data property restrictions. And if property
>>>restrictions with no explicit property definitions are allowed in
>>
>>owl-dl
>>
>>>we have to support their editing in growl.
>>>
>>>
>>>
>>>So what we have to do with so called  "non typed" property restriction
>>
>>>-allow them in growl or banish them from growl? Any of your thoughts
>>
>>on
>>
>>>this subject would be welcome.
>>>
>>>
>>>
>>>Thanks,
>>>
>>>Serguei
>>>
>>
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