Re: an LDP ontology -- Was: MothersLovers - an OWL restriction question

Hi Henry and Brian, 

if i understand Henry's motivating example correctly, you want a class expression that describes those people who love their mothers, i.e., they are related by the 'loves' to their mothers, i.e., there is a person who they are related to by both the 'loves' property and the 'hasMother' property. 

If this is correct, here is a trick: 

- specify a sub-property chain axiom, saying that "loves o isMotherOf" is a Subpropertychain of "P" (notice I use the *inverse* of 'hasMother' here - so every MotherLover should be P-related to themselves - and possibly also to other things)

- define "MotherLover" as an EquivalentClass of "P some self" 

…that should do it in the following sense: if you happen to have a known person who loves their mother, they will be returned if you ask for instances of "MotherLover"…

It doesn't quite work, however, in the following sense: if you *declare* somebody to be an instance of MotherLover, then they won't necessarily have to love their mother (they will only be P-related to themselves - the subpropertychain is only an implication, not a bi-implication…)

All the best, cheers, Uli 

On 14 Mar 2014, at 15:45, "henry.story@bblfish.net" <henry.story@bblfish.net>
 wrote:

> 
> On 14 Mar 2014, at 15:40, Brian Ulicny <bulicny@vistology.com> wrote:
> 
>> I think you are looking for a SELF-restriction here:
>> 
>> http://www.w3.org/2007/OWL/wiki/New_Features_and_Rationale#F4:_Self_Restriction
>> 
>> This is not part of OWL 2 RL, but you can easily write a rule for this.
> 
> Thanks Brian,
> 
>   that's how I started, then I had doubts, and paddled back. I just checked the formal definition 
> on the owl-direct-semantics [1] page and as I read it, it seems to say that something 
> has an owl:hasSelf if at least one relation relates back to it. I was not sure about that 
> when I looked at the owl2-primer.
> 
> I have been developing a little ontology it order to see if the LDP group that is in LastCall 2 [0] has well defined
> its model. There is something that has struck people as quite odd in the way the ontology is specified, especially
> with the container hierarchy https://www.w3.org/2012/ldp/wiki/ContainerHierarchy 
> 
> So I tried to see if one could unify all the containers by introducing the notion of a binding rule, which would
> show how the different container types can be specified by restrictions on the number and types of the 
> ldp:bindingRule relation. This lead me to the following ontology:
> 
>   https://github.com/bblfish/ldp/blob/master/ldp.binding.ttl
> 
> A binding rule, relates a container to a statement about what happens as a rule
> when one POSTs something to the container. So in philosophy of language 
> it is similar to a specification of a speech act. ( When a priest utters the words "you are now
> man and wife he is not describing reality, but he is making the statement true. Same when
> a chair utters the words "the meeting is now closed" ).
> 
> This ontology uses an owl:hasSelf restriction on property defined via a propertyChainAxiom.
> It gives the correct class hierarchy with Pellet, but since Pellet complains a lot I can't be
> sure if this really is consistent.
> 
> Does anyone have a reasoner that could check the consistency of it?
> 
> $ sh pellet.sh classify --input-format  Turtle -l jena ../LDP/ldp.binding..ttl 
> Mar 14, 2014 4:11:24 PM org.mindswap.pellet.RBox ignoreTransitivity
> WARNING: Unsupported axiom: Ignoring transitivity and/or complex subproperty axioms for isMemberOfRelation
> Mar 14, 2014 4:11:24 PM org.mindswap.pellet.RBox ignoreTransitivity
> WARNING: Unsupported axiom: Ignoring transitivity and/or complex subproperty axioms for hasMemberRelation
> Mar 14, 2014 4:11:24 PM org.mindswap.pellet.RBox ignoreTransitivity
> WARNING: Unsupported axiom: Ignoring transitivity and/or complex subproperty axioms for insertedContentRelation
> Mar 14, 2014 4:11:24 PM org.mindswap.pellet.RBox ignoreTransitivity
> WARNING: Unsupported axiom: Ignoring transitivity and/or complex subproperty axioms for membershipResource
> Classifying 14 elements
> Classifying:  100% complete in 00:00
> Classifying finished in 00:00
> 
>  owl:Thing
>     rdf:Property
>     rdfs:Resource
>     ldp:HTTPActionRule
>        ldp:IndirectBindingRule
>           ldp:DirectBindingRule
>              ldp:ContainerRule
>     ldp:Resource
>        ldp:Source
>           ldp:Container
>              ldp:DirectContainer
>                 ldp:IndirectContainer
>                    ldp:BasicContainer
> 
> Btw. the central networth example from the spec, can be re-written with the binding rule
> as follows:
> 
> @prefix dcterms: <http://purl.org/dc/terms/>.
> @prefix o: <http://example.org/ontology/>.
> 
> </netWorth/> a ldp:DirectContainer;
>    dcterms:title "The assets of JohnZSmith";
>    ldp:bindingRule [ a ldp:DirectBindingRule;
>         ldp:subject </netWorth/nw1/>;
>         ldp:relation o:asset;
>       ];
>    ldp:contains </netWorth/a1>, </netWorth/a2> .
> 
> 
> 
> ( So that was the more serious example I mentioned )
> 
> 
> Henry
> 
> [0] http://www.w3.org/TR/ldp/
> [1] http://www.w3.org/TR/2012/REC-owl2-direct-semantics-20121211/#Class_Expressions
> 
> 
> 
>> 
>> Best regards,
>> 
>> Brian Ulicny, PhD
>> Chief Scientist
>> VIStology, Inc
>> 
>> 
>> On Fri, Mar 14, 2014 at 10:31 AM, <henry.story@bblfish.net> wrote:
>> 
>> I would like to specify the class that is such that the object of one relation
>> is the same ( or same domain ) as object of another relation.
>> 
>> Something that could be written like this ( were it to exist )
>> 
>> SomeType
>> owl:equivalentClass
>>       [ a owl:SameRangeRestriction;
>>         owl:onProperty :rel1;
>>         owl:onProperty :rel2
>>       ] .
>> 
>> One could define the class of lovers of their mothers like that
>> 
>> MothersLovers owl:equivalentClass [ a owl:SameRangeRestriction
>>                            owl:onProperty :lover
>>                            owl:onProperty :mother ] .
>> 
>> As that SameRangeRestriction does not exist, I tried this:
>> 
>> MothersLovers
>>    owl:equivalentClass [ a owl:Restriction;
>>               owl:onProperty [ rdfs:subPropertyOf [ owl:propertyChainAxiom ( :lover [ owl:InverseOf :mother ] )];
>>                                a owl:ReflexiveProperty ];
>>               owl:minCardinality 1 ] .
>> 
>> 
>> But Pellet does not like property chain axioms in Restrictions. ( perhaps other resoners allow this?)
>> Is there some way to do this properly? ( I do have a real use case, but it's more complex to explain )
>> 
>> Henry
> 
> Social Web Architect
> http://bblfish.net/
>

Received on Saturday, 15 March 2014 01:34:57 UTC