Re: [ontolog-forum] Current Semantic Web Layer Cake

["Adrian Walker" <adriandwalker@xxxxxxxxx>]

Hi Sean  --

Good to see that I seem to have understood your "real world concerns more or less correctly.

You wrote....

The problem is that the word 
"semantics" seems to cover a family of related meanings. Perhaps we ought to 
qualify what we want to mean by different flavours of semantics. I will offer 
the following outrageous suggestion (enough to keep Pat raging for a couple of 
days :-))

    Semantics - the behaviour of a set of terms and operations in a system:

        Real world semantics: how people and machines behave in response to input;

        Logicians' semantics: A set of terms T some superset of {TRUE, FALSE} and a set of operations O:T -> T

Yes indeed.  Someone commented a while ago that "semantics" is
a word with perhaps the most different meanings.  From one point
of view that's just humorous.  But it has dire real world
consequences for those of us concerned with building real world systems.

Another suggestion [1] is to distinguish

            Semantics1  -- the meaning of data, as in XML, RDF,...

          
Semantics2  --  logical model theory used guide
implementation of correct provers [2]

          
Semantics3  --  the real world meaning of English sentences

BTW, the declarative and procedural concerns come together usefully
when one  looks at generated proofs/explanations as plans
[3].  With regard to the procedural meaning of security
classifications, [4] may be of interest.

                                            
Cheers,  -- Adrian

[1]  www.reengineeringllc.com/A_Wiki_for_Business_Rules_in_Open_Vocabulary_Executable_English.pdf

[2]  Backchain Iteration: Towards a Practical Inference Method that is Simple 
  Enough to be Proved Terminating, Sound and Complete. Journal of Automated Reasoning, 11:1-22

[3]  www.reengineeringllc.com/demo_agents/ProcessSpecificationLanguage1.agent

[4]  www.reengineeringllc.com/demo_agents/Access.agent

Internet Business Logic (R)
A Wiki for Executable Open Vocabulary English
Online at www.reengineeringllc.com    Shared use is free

Adrian Walker
Reengineering

On 8/7/07, Barker, Sean (UK) <Sean.Barker@xxxxxxxxxxxxxx> wrote:

Adrian, John, Pat

 

    Adrian is right about my concern is the effect on the real world. Although I haven't studied the history of logic, I'm hardly surprised that the various independent formulations of two valued logic are isomorphic to FOL (or at least homomorphic to some subset of FOL). However, if you were to start with a set of truth tables and systematically changed True to False and vice versa, and AND to OR and vice versa (though NOT remains the same) then you would apparently have the same system, even through True is now False.

 

    The industrial problem is not semantics "as a game played this way", but the behaviour of a system (=people + procedures + goals + materiel, including computers), and the difficulty is more in demonstrating that the logic is applicable to situation of interest. I expect you are familiar with supermarket mathematics where 1+1 = 1 (or buy one get one free), and possible the economic 'logic' that goes with such promotions.

 

    Yes, Pat is right that procedures are more difficult to formalise. The problem is that much of the information we want to pass is actually procedural. The classic example is "security classification". The marking "secret" is not there to describe the content, but defines a number of procedures about what one may or may not DO with a document (e.g. you may not photocopy it), and interchange of secret documents is subject to demonstrating the organization has and follows the same procedures. Similarly, buying and selling are learned buying sweets (candy) in shops at the age of five - and it works on the web because the web process follows the same pattern as everyday procedures. Data exchange is painful not because the definitions are in principle so difficult, but because we have never tried to share across such different organizations and cultures before, and we are still learning how to do it. Anyone moving to a new job will be familiar with the experience of getting to know the organization, its procedures and the peculiar local terminologies (particularly job titles).

 

    The problem is that the word "semantics" seems to cover a family of related meanings. Perhaps we ought to qualify what we want to mean by different flavours of semantics. I will offer the following outrageous suggestion (enough to keep Pat raging for a couple of days :-))

    Semantics - the behaviour of a set of terms and operations in a system:

        Real world semantics: how people and machines behave in response to input;

        Logicians' semantics: A set of terms T some superset of {TRUE, FALSE} and a set of operations O:T -> T

 

More seriously, I would find it useful if the professional philosophers, logicians and computer scientists could agree a taxonomy of the uses of "semantics", and then establish them by frequent use on the forum.

Sean Barker
Bristol, UK

This mail is publicly posted to a distribution list as part of a process of public discussion, any automatically generated statements to the contrary non-withstanding. It is the opinion of the author, and does not represent an official company view.

 

 

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