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From: bwk@mbunix.mitre.org (Barry W. Kort)
Newsgroups: comp.lang.smalltalk
Subject: Re: SmallTalk V/286 - Some questions..
Summary: We tried it.  We like it.
Keywords: Model-based and rule-based reasoning, continuous-valued logic
Message-ID: <62754@linus.UUCP>
Date: 6 Aug 89 13:19:33 GMT
References: <378@DB0TUI11.BITNET>
Sender: news@linus.UUCP
Reply-To: bwk@mbunix (Barry Kort)
Organization: The MITRE Corporation, Bedford, Mass.
Lines: 27

In article <378@DB0TUI11.BITNET> MUHRTH@DB0TUI11.BITNET (Thomas Muhr) 
asks some questions about DigiTalk Smalltalk V/Mac:

 > Is the built-in prolog-engine of any use ?

We use the Prolog classes for a rule-based diagnostic expert
system which analyzes fault and overload conditions in a
color-animated smalltalk model of a local area network (LAN).

The basic LAN model is coded in Smalltalk.  The user can
instruct various components of the model to misbehave in
interesting ways.  The expert system then has to diagnose
the problem based on observed behavior of the model as
reported by Lanalyzer measurements of collision events
and statistical counts of packets and acknowledgements.

We are using continuous-valued logic, so the diagnostic expert
system forms an evolving opinion about the hypothetical fault
conditions as confirmatory and exculpatory evidence trickles
in over time.

At the present time, there are only a few dozen rules, and
the expert system is of modest scope.  But it demonstrates
the potential for integrated model-based and rule-based
paradigms for simulation, inference, and diagnostic reasoning.

--Barry Kort