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Re: LANG: OWL non-xml syntax

From: Frank van Harmelen <Frank.van.Harmelen@cs.vu.nl>
Date: Fri, 22 Mar 2002 21:32:49 +0100
Message-ID: <3C9B94F1.2000907@cs.vu.nl>
To: Jonathan Borden <jonathan@openhealth.org>
CC: WebOnt WG <www-webont-wg@w3.org>
Jonathan Borden wrote:

> It is often helpful to have a non-XML syntax, which is often more human
> readable.
> 
> In the process of merging the proposed OWL abstract syntax with DAML+OIL,
> and in creating this non-XML syntax in the process, a few issues have arisen
> (this is why this process is often helpful)
> 
> First an simple example of the non-XML syntax:
> http://www.openhealth.org/WOWG/Schema.onx  -- note that I am using the "onx"
> suffix for "OWL Non-xml"
> Second, the simple Schema from which this was derived:
> http://www.openhealth.org/WOWG/Schema.owl
> Third, the surface syntax,
> http://www.openhealth.org/WOWG/OWLnonXMLsyntax.txt which is derived from
> http://www.cs.vu.nl/~frankh/spool/OWL-first-proposal/frame.html , note that
> this is not yet complete pending resolution of these issues, (and perhaps a
> few others :-))
> 
> 1: What distinguishes "DefinedClass" from "PrimitiveClass", there is nothing
> in the abstract syntax which helps?


A PrimitiveClass lists necessary conditions for membership, but these do not 
have to be sufficient conditions. Thus:
if x is a member of the class,
then the conditions described in the definition are true for x
(but not necessarily the other way round).

A DefinedClass lists necesary and sufficient conditions for membership, thus 
not only is an member of the class guaranteed to satisfy these conditions, but 
also anything for which these conditions hold is a member of the class.


> 2: What is the syntactic differenence between an "Individual" and a "Fact"?


Not sure what you mean. There is no symbol "Fact" in [1].
A "<fact>" which is of the form Indivisual(...), states facts about an individual.

Frank.
    ----
Received on Friday, 22 March 2002 15:33:42 GMT

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