Re: definitionOf

1. speciesOf vs. subClassOf, using the example Classes man, person, animal.
 a. man is person
     if and only if  man has sameAs = person
     which means that the set of all men is identical to the set of all persons (in Aristotle's context)
 b. man iss animal
     if and only if  man has speciesOf = animal
     which means that the set of all men is a proper subset of the set of all animals
 c. man iss* animal
     if and only if  man has subClassOf = animal
     which means that either the set of all men is identical to the set of all animals
                                or      the set of all men is a proper subset of all animals
The advantage of iss (speciesOf) over iss* (subClassOf) is that it provides a more precise foundation for logical inference on Class hierarchies.
The inverse of "iss" is "isg" (is the genus of).
The inverse of "isu" is "isp" (is the primitive concept of).

2. individualOf vs. type
 a. subject isu object
     iff subject has individualOf = object
     subject must be an individual
 b. subject has type = object
     subject can be any individual or any subClass of object

3. definitionOf expressed in triples
I have not made any specific proposal for representing this "quad" in triples.
Genus and differentia are not independent properties because definitions are context-dependent.
In the alternative syntax of the KR language, a definition is expressed directly as
    subject isu genus with differentia
    subject iss genus with differentia
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart list of proposition

  ----- Original Message ----- 
  From: Jon Hanna 
  To: public-webont-comments@w3.org 
  Cc: RDF-Interest 
  Sent: Monday, November 18, 2002 11:26 AM
  Subject: RE: definitionOf



  > I contend that the OWL language [1] is missing three
  > essential properties:
  >
  >       definitionOf
  >       speciesOf
  >       individualOf

  What is the difference between the proposed owl:individualOf and rdf:type?

  How do you propose to express owl:definitionOf in triples? What would
  differentiate that from being a combination of owl:subClassOf (or
  rdfs:subClassOf) and whatever triples one would need to express the
  differentia.

  What advantages does speciesOf have over a combination of owl:subClassOf (in
  one direction) and the owl:inverseOf owl:subClassOf (in the opposite
  direction) - is it intended to be a short hand for this?