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Re: facts of reality, context, possible worlds

From: Richard H. McCullough <rhm@cdepot.net>
Date: Tue, 10 Dec 2002 15:21:52 -0800
Message-ID: <001401c2a0a2$ed01a7d0$bd7ba8c0@rhm8200>
To: "pat hayes" <phayes@ai.uwf.edu>
Cc: "RDF-Interest" <www-rdf-interest@w3.org>, "Richard S. Latimer" <latimer1@att.net>
Re: facts of reality, context, possible worldsThis email covers issues raised in emails of December 4,5,6.
My new comments are prefixed with #####.
============ 
Dick McCullough 
knowledge := man do identify od existent done
knowledge haspart proposition list

1. the purpose of the Semantic Web
a. Dick: to provide man and machine with easy access to the facts of reality.
b. Pat: is to make propositional content available to machine processing on the Web.
##### Let's take one step back & get our priorities straight.
##### The purpose of the internet/Semantic Web is to facilitate communication between men.
##### The purpose of machine is to assist men.

 2. selective view of reality
a. Dick: It is not necessary to pin down the actual world in full detail.  You can select the appropriate level of detail, depending on your purpose, and express it in KR propositions.
b. Pat: Then KR is exactly like all other languages. Getting this idea of 'level of detail' pinned down precisely will involve a semantic theory, and if you try to construct one with a mathematical level of rigor you will probably find yourself rediscovering Tarski's ideas.
##### You don't need a mathematical model.  Humans do this selection all the time.
##### Selection of the facts is the appropriate first step, prior to encoding those facts for the Semantic Web.
c. Dick: The real world is too hard, so we'll deal with imaginary worlds.
d: Pat: Bad paraphrase ... not too hard, but too large.
##### From the perspective of epistemology (theory of knowledge):
##### the purpose of concepts is to reduce "too large" so the limitied human mind can process it;
##### the purpose of definitions is to condense vast amounts of info. about concepts.

3. meaning and "P and not P"
a. Dick: The meaning of any KR proposition is the facts of reality which it denotes.
b. Pat: That sentence doesn't make sense ... if KR has the power of English ... then it can express a sentence of the form 'P and not P' for some proposition P. Now, there cannot be any facts of reality denoted by such a sentence: it has to be false. So on your criteria, it would presumably be meaningless. But it is not  meaningless: it says that P is both true and false, which is clearly meaningful if P is; that is how we know it must be false.
##### The appropriate terminology is 
##### "P and not P" is: (1) well-formed (correct syntax); (2) false; (3) meaningless (semantics).

4. meaning and "tabula rasa"
a. Dick: The meaning of this KR proposition is immediately obvious to any English-speaking adult.  
at view=tabula rasa { Dick isa person; Dick has sex=male }
b. Pat: ... it isn't to me, for example (I have no idea what you mean by 'tabula rasa'); ...
#####  Excellent point.  I think it would be understandable if I deleted "at view=tabula rasa {" and "}".
##### "tabula rasa" specifies the meaning of isa, has, person, sex, male
##### (and existent, attribute, action, relation, proposition, haspart, do, ...)

5. KR vs. English
a. Pat: ... if KR is on a par with English, then why not just use English? KR *looks* like an attempt at a formal language, not just another notation for human natural language. 
##### English is ambiguous, redundant, complex.
##### KR is unambiguous, non-redundant, simple.

6. KR has solved the central AI problem
a. Dick: Although Knowledge Explorer (KE) does not "understand" this proposition in the same sense as a human, KE can reason" ffectively using its internal entity-characteristic-proposition taxonomy. 
b. Pat: Claiming to be able to reason effectively in a language with the expressive power of English is a very large claim, and one that I am afraid I cannot take seriously. If you could do this, you would have solved the central AI problem ...
##### I believe that I have by (1) focusing on meaning and context; (2) identifying the essential characteristics of attribute, part, relation, proposition; (3) using genus-differentia definitions.

7. context
a. Dick: Re principles, I have identified the essential characteristics of context.
b. Pat: I don't agree that you have.  Certainly the community as a whole is not, I believe, convinced that you have.   You need to write a book about your ideas, or a few papers at least.
##### Exactly who is "the community"?
##### What did "the community" say AFTER they read my KE tutorial?
c. Dick: Re working, I have used KR/context very successfully for 6 years, in many different domains.
d. Pat: Used it for what?
##### Many things, from expense records to concept formation.
##### I invite you to browse my web pages http://rhm.volcano.net/~rhm/knowledge.  You will find about 600 files filled with notes on examples, application and theory.

8. space-time context
a. Pat: I know you can ask these questions about the 'context' of an action, since actions always happen at a time and place (well, strictly, that isn't true, but it's a handy fiction for most purposes)
##### Can you give me some examples of when it isn't true?
b. Pat (my paraphrase): Why is space-time part of context?
##### Here's a motivating example.
##### context 1: I spent Wednesday at home.  I had lunch and watched Star Trek.  I went to Payless grocery store.
##### context 2: On Saturday, I visited my brother.  On Sunday we had breakfast and went to Fry's electronics store.
##### Taking "going to the store" to be the selective view of reality which is of interest, the KR expression of the facts is
##### at space=my house, time=Wednesday afternoon { I do go to Payless grocery store done }
##### at space=my brother's house, time=Sunday morning { my brother, I do go to Fry's electronics store done }

9. KR expression of your examples
a. Joe suddenly turned to face the Count.
b. As Susan went into the kitchen, Bill smiled enigmatically at Josephine.
c. It was clear that someone had been in the room recently.
##### at space=a house, time=past, view=tabula rasa {
#####    Joe, the Count, Susan, Bill, speaker isa person;
#####    ... etcetera ...
#####    Joe do turn with suddenly, purpose={ Joe do face od the Count done } done;
#####    Susan do go to the kitchen done causes Bill do smile at with enigmatically od Josephine done;

#####        speaker do think with it is clear od { 
#####            forSome someone isa person {
#####                at time=recently { $someone isin the room };
#####            }; # end forSome someone
#####        } done;  # end think
#####    }; # end present
##### } # end view=tabula rasa
Received on Tuesday, 10 December 2002 18:21:55 GMT

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