Re: input document for discussion on Friday

On Wed, Oct 31, 2012 at 1:16 PM, Philipp Cimiano <
cimiano@cit-ec.uni-bielefeld.de> wrote:

> **
> John, all,
>
>  comments back...
>
> Am 31.10.12 12:59, schrieb John McCrae:
>
> Hi,
>
>  Some comments
>
>   ex:lemon rdf:type ontolex:Lex.
>> ex:lemon ontolex:hasSense lemon_1.
>> lemon_1 owl:subClassOf <http://dbpedia.org/page/Lemon>.
>> ex:lemon ontolex:hasSense lemon_2.
>>
> Thus :lemon_2 is an individual
>
>> lemon_2 owl:subClassOf ex:DefectiveItem.
>
> Thus :lemon_2 is a class
>
>  This leads to a punning of the sense... is this intended?
>
>
> Yes, intended to capture the dual role of a sense.
>
>
>
>   And further (not expressible in OWL2 DL):
>> ∀x; y lex(x; y) ∃s Sense(s) ^ hasSense(x; s) ^ representedBy(s; y)
>
>
>  I really don't think we should go beyond OWL2 DL
>
>
> We will not. This is simply not expressable in OWL2 DL. This is an axiom
> that might need to be ensured in implementations or not at all. To be
> discussed.
>
>
>   it is true that it blows up the complexity of the
>> model. However, it simplifi es the usage of the model
>
> Surely this is a contradiction?
>
>
> No, it's not. The model is in principle more complex, but people use
> always that subset that fits their need. They have their own simple view on
> a complex model.
>
>
>   I think this can be handled eff ectively by query expansion (as above)
>> in any
>> implementation of an API for the lexicon-ontology model
>
> Not all implementations will be query based... for example OWLAPI isn't
>
>
> Sure, there will be different ways of implementing this. Query expansion
> is not the only one. Relying on OWL reasoning is another one.
> SPARQL construct is another one. And a procedural API-specific
> implementation is another one. We could provide some recommendations on
> this. I am not suggesting that we ignore implementaiton, but that we do not
> put it at the centre of our discussions.
>
>
>  This can be done through SPARQL-construct
>
>  The construct query is:
>
>  CONSTRUCT { ?entry ontolex:hasSense _:sense .
>                              _:sense ontolex:representedBy ?entity }
>  WHERE {
>      ?entry ontolex:ref ?entity
> }
>
>  Of course, this leads to issues as the constructed sense is a blank
> node... I believe that like OWL we should advise against the use of blank
> nodes for "concepts" within the lexicon. See
> http://richard.cyganiak.de/blog/2011/03/blank-nodes-considered-harmful/
> http://milicicvuk.com/blog/2011/07/14/problems-of-the-rdf-model-blank-nodes/
>  etc.
>
>  ex:lemon rdf:type ontolex:Lex.
>> ex:lemon ontolex:hasSense lemon_1.
>> lemon_1 ontolex:representedBy <http://dbpedia.org/page/Lemon>.
>> ex:lemon ontolex:ref <http://dbpedia.org/page/Lemon>.
>
>
>
>  Then the question certainly is how many senses I get back with the query.
>> Ideally, I would like to get one sense back.
>
>  Yeah technically that is what should happen... however here we have to
> apply the semantics of RDFS, in that the blank node we construct is matched
> to lemon_1. Of course, the downside to this is that this is non-polynomial
> to solve with generic solvers... and tricky in a specialized implementation
> (also I think it is incompatible with OWL2-DL)
>
>  One question: do we want to model that for any pair of class and lex,
>> there
>> is at most one sense relating them? Can we do this in OWL?
>
>  I would say no, I think we have found use cases for multiple sense
> between the same entry/entity in *lemon* (but can't remember at the
> moment... it'll come to me)
>
>  As for in OWL... is this not it?
>
>
>  ⊤⊑1.lex.Lex
>
>  No, this says that there is exactly one lexicalization per concept ;-)
>
Yeah that was dumb.... actually, it may not be possible

A good start is
represents ∘ represents⁻¹ ≡ sameRep
sense⁻¹ ∘ sense ≡ sameLex

Then the very simple axiom does the trick

∀ x,y : sameRep(x,y) ∧sameLex(x,y) → x = y

However this is (probably) impossible to represent in OWL:

http://answers.semanticweb.com/questions/2336/preventing-other-individuals-in-a-class-from-inferring-the-same-property#2338

I don't know if there is another way

Regards,
John

>
>
>  Regards,
> John
>
>  On Wed, Oct 31, 2012 at 9:45 AM, Philipp Cimiano <
> cimiano@cit-ec.uni-bielefeld.de> wrote:
>
>> Dear all,
>>
>>  I have compiled a brief document as input for our discussion on Friday.
>> We will discuss this proposal on Friday and collect comments and objections.
>>
>> Best regards,
>>
>> Philipp.
>>
>> --
>> Prof. Dr. Philipp Cimiano
>> Semantic Computing Group
>> Excellence Cluster - Cognitive Interaction Technology (CITEC)
>> University of Bielefeld
>>
>> Phone: +49 521 106 12249
>> Fax: +49 521 106 12412
>> Mail: cimiano@cit-ec.uni-bielefeld.de
>>
>> Room H-127
>> Morgenbreede 39
>> 33615 Bielefeld
>>
>>
>
>
> --
> Prof. Dr. Philipp Cimiano
> Semantic Computing Group
> Excellence Cluster - Cognitive Interaction Technology (CITEC)
> University of Bielefeld
>
> Phone: +49 521 106 12249
> Fax: +49 521 106 12412
> Mail: cimiano@cit-ec.uni-bielefeld.de
>
> Room H-127
> Morgenbreede 39
> 33615 Bielefeld
>
>