# KEHOME/doc/definitionOf.txt
# Nov/19/2002

owl:definitionOf
================
Author: Richard H. McCullough
Date: November 19, 2002

Contents
========
Abstract
speciesOf and individualOf
definitionOf
Example: man is a rational animal
References


Abstract
========
The OWL language [1] is missing three essential
properties:

	definitionOf
	speciesOf
	individualOf

The remainder of this document briefly describes these
properties and gives an example: Aristotle's definition
of man: "man is a rational animal".

In the spirit of allowed alternative syntax [1],
this document uses the syntax of [3],[4].

speciesOf and individualOf
==========================
The OWL guide [2] recognizes the importance of distinguishing
between classes and individuals.  I propose that two new
properties be added to OWL to facilitate the distinction:

	subject has individualOf = object
	subject has speciesOf = object

"speciesOf" differs from "subClassOf" and "subPropertyOf"
because it excludes "sameAs".  In the terminology of set
theory, "speciesOf" denotes a proper subset.

These two properties can be more simply expressed as: 

	subject isu object
	subject iss object

("u" stands for unit, which is another name for individual.)


definitionOf
============
definitionOf is a ternary relation:

	definitionOf subject genus differentia

which may be expressed as

	subject isu genus with differentia
	subject iss genus with differentia

"genus" is the Class or Property which subsumes the "subject".
"differentia" is the set of essential properties which
distinguish the "subject" from other members of "genus".

Example: man is a rational animal
=================================
In the alternative syntax of [3],[4], this definition is

	man iss animal with rational

"man" is a species of the genus "animal".
"rational" is the property of "man" which distinguishes
man from other animals.


References
==========
[1] OWL language reference
    "http://www.w3.org/TR/2002/WD-owl-ref-20021112/"
[2] OWL guide
    "http://www.w3.org/TR/2002/WD-owl-guide-20021104/"
[3] KR language
    "http://rhm.cdepot.net/doc/KRgrammar.txt"
[4] KR implementation
    "http://rhm.cdepot.net/doc/KEtutorial.txt"
