Re: proposed response for ml

From: Jim Hendler <>
Subject: Re: proposed response for ml
Date: Wed, 9 Apr 2003 13:53:33 -0400

> Peter - I think this would handle things right, and we could reopen 
> the issue of whether owl:nothing should be in Lite.  I have one small 
> suggestion
> >I believe that the explanatory text adequately makes the distinction
> >between named and anonymous individuals, and that there does not need to be
> >separate productions for them, particularly as the productions are very
> >similar.
> How about citing some of the relevant text and saying
> The following text
>   " ... "
> explains the difference between named and anonymous individuals, 
> There does not need to be separate productions for them as the 
> productions are very similar.
> this way, you can direct him to the particular part of the document 
> that answers his question, rather than making him search for it.
>   -JH

OK, here is the revised response:

Again, thank you for your comments.   In this message I propose some
editorial and tyopgraphical changes that I think might help to address
most of them.

> 1. 
> [2.1. Ontologies 
> There are two built-in classes in OWL,....
>  The class with identifier owl:Thing is the class of all individuals, and
> is part of OWL Lite. The class with identifier owl:Nothing is the empty
> class.  
> ...
> ]
> It should be explicitly specified whether or not owl:Nothing is included
> in OWL Lite.  

I have made the editorial change to add ``, and is part of OWL DL, but not
part of OWL Lite'' at the end of the above quote.

> It would be nice and elegant to include owl:Nothing in OWL Lite if there
> is no harm to do so. 

It was a working group decision to not include owl:Nothing in OWL Lite,
even though an equivalent class can be defined in OWL Lite.  Your comment,
however, will be considered by the working group.

> 2.
> [2.3. Axioms
> ...
> However, **most information about properties** is more naturally
> expressed in restrictions, which allow local range and cardinality
> information to be specified.  
> ...
> ]
> Restrictions are about to define new classes, not to specify
> properties. So the above sentence should be modified if possible.  

Information about properties is not exactly specifying those properties.  I
do agree, however, that this sentence could be said better, so I've changed
it to read ``most information concerning how properties'' .  It would also
be possible to write a much longer explanation of the difference here, but
I feel that that would not be helpful here.

> 3.
> [ OWL Lite Restrictions
> cardinality ::= 'minCardinality(0)' | 'minCardinality(1)' |
>             | 'maxCardinality(0)' | 'maxCardinality(1)' |
>             | 'cardinality(0)'    | 'cardinality(1)'
> ]
> There are two reduantant symbols '|'.

Thanks for noticing.  I made the typographical change to eliminate them.

> 4. About individual
> Just suggestion:
> The named individual and the anonymous individual should be explicitly
> separated. There are some essential differnce between facts about named
> individuals and the ones about anonymous individuals.  

I believe that the following explanatory text from Section 2.2 

	An individual can be given an individualID that will denote that
	individual, and can be used to refer to that individual.  However,
	an individual need not be given an individualID; such individuals
	are anonymous (blank in RDF terms) and cannot be directly referred
	to elsewhere.  The syntax here is set up to somewhat mirror RDF/XML
	syntax RDF Syntax without the use of rdf:nodeID.

adequately makes the distinction between named and anonymous individuals.
I also believe that there does not need to be separate productions for
them, particularly as the productions are very similar.

> Yuzhong Qu
> Dept.Computer Science and Engineering
> Southest University, Nanjing, China

Please reply to the mailing list as to whether the above changes adequately
address your comments (except for whether owl:Nothing is in OWL Lite, which
will be separately addressed).

Again, thank you.

Peter F. Patel-Schneider
Bell Labs Research
Lucent Technologies

Received on Monday, 14 April 2003 09:45:27 UTC