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Re: Inferring Class Membership w/o OWL Full?

From: Pat Hayes <phayes@ihmc.us>
Date: Fri, 7 May 2004 22:47:43 -0500
Message-Id: <p06001f39bcc20547afd0@[10.0.100.76]>
To: Ian Horrocks <horrocks@cs.man.ac.uk>
Cc: Stephen Rhoads <rhoadsnyc@mac.com>, www-rdf-logic@w3.org

>For those who didn't follow the debates on the webont mailing list, I
>should perhaps draw your attention to the sad history of Pat's morbid
>obsession with DLs. I had hoped that having recognised the problem [1]
>(the first and hardest step) he would by now be well on the road to
>recovery. Sadly, it would appear that this is not the case. In fact
>this is not Pat's first relapse [2], so perhaps we shouldn't be
>surprised.
>
>Ian
>
>[1] http://lists.w3.org/Archives/Public/www-webont-wg/2002Sep/0411.html
>[2] http://lists.w3.org/Archives/Public/www-webont-wg/2002Dec/0092.html

Perhaps also not uncharacteristically, Ian manages to simultaneously 
be insulting, offensively ad-hominem and to mislead the unwary 
reader.  The acknowledgement in [1] was to a completely unrelated 
misunderstanding arising in part from my reaction to an extended 
series of memoranda claiming to show that (what is now called) 
OWL-Full was impossible, by a specious reference to the set-theoretic 
paradoxes, but also in part, I concede, from my own ignorance of DL 
metatheory at that time. The opinions I expressed in [2] are 
unrelated to [1] , are not a 'relapse' - to acknowledge that DLs are 
a subset of FOL is not to endorse the basing of the entire SW effort 
on that subset - and I still hold them, and will continue to hold 
them.

I won't react to such jibes in future, but the record should be set straight.

Pat

>
>On May 7, Pat Hayes writes:
>>
>>  >I realize that everyone is probably beat from that "Classes as
>>  >Values" discussion in the SWBP, but ... no thoughts on this?
>>  >
>>  >Would it be unthinkable to create a subPropertyOf rdf:type?
>>
>>  Its explicitly forbidden in OWL-DL by edict of the DL police, but it
>>  makes perfect semantic sense and could be done in OWL-Full. On the
>>  other hand, why not just use rdf:type? What do you gain from the
>>  explicit subpropertying?
>>
>>  If you thought to sneak past the DL syntax restrictions, forget it.
>>  The DL police have already thought of all the tricks you could use
>>  and blocked all the exits.
>>
>>  Pat
>>
>>  >Something like ...
>>  >
>>  ><owl:ObjectProperty rdf:ID="hasGenre">
>>  >    <rdfs:subPropertyOf rdf:resource="&rdf;type"/>
>>  ></owl:ObjectProperty>
>>  >
>>  ><ex:Song rdf:ID="PurpleHaze">
>>  >    <ex:hasGenre rdf:resource="&ex;ClassRockMusic"/>
>>  ></ex:Song>
>>  >
>>  >Thus, the Individual "PurpleHaze" is an instance of both Song and
>>  >ClassicRockMusic.
>>  >
>>  >Note that the intent is state class membership, not to say that the
>>  >"subject" of the Song is a concept denoted by a Class (as in the
>>  >"Classes as Values" paper).
>>  >
>>  >--- Stephen
>>  >
>>  >
>>  >On Apr 24, 2004, at 4:50 PM, Stephen Rhoads wrote:
>>  >
>>  >>
>>  >>Folks,
>>  >>
>>  >>There are various parts of my (Media Publishing and Distribtuion)
>>  >>ontology where I would like to avoid the requirement of "multiple
>>  >>typing".  The objective here is to simplify the ontology and user
>>  >>interfaces which employ it.
>>  >>
>>  >>A user of the ontology should be able to simply declare an
>>  >>Individual to be a Song, Album, Movie, MovieSeries,
>>  >>TelevisionProgram, TelevisionSeries, RadioProgram or RadioSeries.
>>  >>Other important class membership should be inferred by property
>>  >>values.  A TelevisionSeries, for example, could have
>>  >>"hasSeriesType" of "SeasonalSeries" and thus be a member of that
>>  >>Class.  A Movie could have "hasGenre" of "Drama" and thus be a
>>  >>Drama.
>>  >>
>>  >>The problem is that I can't see how to model this without landing
>>  >>in OWL Full.  Take the following example:
>>  >>
>>  >>A sample Class hierarchy:
>>  >>
>>  >>Music
>>  >>    ElectronicMusic
>>  >>    PopMusic
>>  >>    RockMusic
>>  >>       ClassicRockMusic
>>  >>       GlamRockMusic
>>  >>       GrungeRockMusic
>>  >>
>>  >>And sample Class description:
>>  >>
>>  >><owl:Class rdf:ID="ClassicRockMusic">
>>  >>    <rdfs:subClassOf rdf:resource="#RockMusic"/>
>>  >>    <owl:equivalentClass>
>>  >>       <owl:Restriction>
>>  >>          <owl:onProperty rdf:resource="#hasGenre"/>
>  > >>          <owl:hasValue rdf:resource="#ClassicRockMusic"/>
>>  >>       </owl:Restriction>
>>  >>    </owl:equivalentClass>
>>  >></owl:Class>
>>  >>
>>  >>In other words, if the Individual (a Song or Album) hasGenre
>>  >>ClassicRockMusic, then it *is* ClassicRockMusic (or at least a
>>  >>member of a Restriction Class with the same class extension).  But
>>  >>(I think) this puts the ontology into OWL Full because
>>  >>ClassicRockMusic is being treated as both a Class and an Individual
>>  >>(I can confirm that Racer will not accept the ontology from Protege
>>  >>because it is "not in OWL DL").
>>  >>
>>  >>Thoughts?  Solutions?
>>  >>
>>  >>--- Stephen
>>
>>
>>  --
>>  ---------------------------------------------------------------------
>>  IHMC	(850)434 8903 or (650)494 3973   home
>>  40 South Alcaniz St.	(850)202 4416   office
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>>  phayes@ihmc.us       http://www.ihmc.us/users/phayes
>>


-- 
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IHMC	(850)434 8903 or (650)494 3973   home
40 South Alcaniz St.	(850)202 4416   office
Pensacola			(850)202 4440   fax
FL 32501			(850)291 0667    cell
phayes@ihmc.us       http://www.ihmc.us/users/phayes
Received on Friday, 7 May 2004 23:47:45 UTC

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