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Re: KR and RDF Redux

From: Richard H. McCullough <rhm@cdepot.net>
Date: Fri, 22 Nov 2002 13:25:46 -0800
Message-ID: <001601c2926d$ba94f510$bd7ba8c0@rhm8200>
To: "Frank Manola" <fmanola@mitre.org>
Cc: "Jon Hanna" <jon@spin.ie>, <www-rdf-interest@w3.org>
Frank
You raised a lot of questions, and I don't think it would be helpful for me to try to address every one individually.  Although I'd be  happy to do that off-list if you like.
In the meantime, I'm going to make a general remarks.

1. You had a long list of concepts with little structure.  If you continue like that you're going to end up with 100,000 properties to describe 10,000 concepts.

2. I checked my bookshelf, and I don't own Sowa's "Knowledge Representation"; I suppose that's a recent book?  I don't think I would find any surprises in his book because I have read a number of his papers, and a book which he edited.

3. As for the example:
English:     John went to the store
RDFS:      <xx:John> <xx:wentTo> <xx:TheStore>
KR:           at past { John do go to the store done }

It was part of my design philosophy for "simplifying English" to avoid changing names to describe verb tenses, plurals, etc.
So instead of "went", I use "go" with a time context.  For some actions, a space context will be needed.  In the early days of KR,
I used the unpleasant form
    at time = past { John do go to space = the store done }
but the assumption here is that context enables me to tell that "past" is a time, and "the store" is a space location.
KR syntax is mostly keywords & comma-separated phrase lists.  I avoided non-English symbols as much as possible.  The keywords in this example are:  at  do  to  the  done
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart list of proposition

  ----- Original Message ----- 
  From: Frank Manola 
  To: Richard H. McCullough 
  Cc: Jon Hanna ; www-rdf-interest@w3.org 
  Sent: Friday, November 22, 2002 12:26 PM
  Subject: Re: KR and RDF Redux


  Richard--

  For one thing, RDF doesn't know anything about parts of *English* 
  speech, just about parts of RDF syntax, so in

        <xx:John> <xx:wentTo> <xx:TheStore>

  "wentTo" is certainly a property as far as RDF is concerned.  For 
  another, if you want to strictly rule out verbs, how do you still allow

  ex:John ex:authorOf ex:theBook

  while ruling out

  ex:John ex:wrote ex:theBook

  ("wrote" is a verb after all;  wouldn't you say the two forms meant the 
  same thing?)

  You could get much more precise in your categories if you wanted, and do 
  something like:

  ex:wentTo rdf:type ex:PastAction
  ex:agent rdf:type rdfs:Property
  ex:agent rdfs:domain ex:PastAction
  ex:agent rdfs:range ex:Person
  ex:where rdf:type rdfs:Property
  ex:where rdfs:domain ex:PastAction
  ex:where rdfs:range ex:Location
  ex:John rdf:type ex:Person
  ex:theStore rdf:type ex:Location

  ex:wentTo ex:agent ex:John
  ex:wentTo ex:where ex:theStore

  (see John Sowa's book "Knowledge Representation" if you want to delve 
  into this kind of thing further).

  In these examples, we're trying to record English statements in a (very) 
  restricted syntax, and in principal you can make that jump as broad or 
  narrow as you like (before you start worrying about the logical 
  machinery necessary to actually *record* the meanings of those 
  statements in a machine-interpretable way).

  Now, how did you say

        <xx:John> <xx:wentTo> <xx:TheStore

  in KR?

  --Frank

  Richard H. McCullough wrote:

  > "WentTo" is not a property.
  > 
  > It's a mixture of a verb (action) and a preposition (relation).
  > 
  > It is my understanding that a property is the analog of an adjective or 
  > an adverb.
  > ============
  > Dick McCullough
  > knowledge <http://rhm.cdepot.net/> := man do identify od existent done
  > knowledge haspart list of proposition
  > 
  >     ----- Original Message -----
  > 
  >     From: Jon Hanna <mailto:jon@spin.ie>
  > 
  >     To: www-rdf-interest@w3.org <mailto:www-rdf-interest@w3.org>
  > 
  >     Sent: Friday, November 22, 2002 10:18 AM
  > 
  >     Subject: RE: KR and RDF Redux
  > 
  > 
  > 
  >      > There are lots of things that KR can express and RDF can't.
  >      > For example (English):
  >      >
  >      >     John went to the store.
  > 
  >     <xx:John> <xx:wentTo> <xx:TheStore>
  > 


  -- 
  Frank Manola                   The MITRE Corporation
  202 Burlington Road, MS A345   Bedford, MA 01730-1420
  mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-875
Received on Friday, 22 November 2002 16:26:01 GMT

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