Re: Question about "Fuzzy expert system".

WSiler (wsiler@aol.com)
Mon, 5 Oct 1998 23:39:06 +0200 (MET DST)

>This is an interesting question. In real life, such as when
>working 'backward' from the facts to possible explanations, this
>is exactly the type of inference which is used:
>
>IF car won't start THEN EITHER: 1. battery is dead OR 2. no gas
>OR 3. starter is broken OR etc.
>
>I can imagine a system which pursues these possibilities in
>parallel, although it will quickly get very messy

We have an expert system for precisely this task. Since in running this program
information must be elicited from the user in a context-dependent fashion, in
that the next question to be asked depends on the anwer to the previous
question, we do not use parallel rule firing, but use sequential rule firing
with backtracking.

The rule above appears as three rules. One advances the hypothesis that the
trouble is in electrical system, one that the trouble is in the fuel system and
one that it is in the ignition system. (We left out compression problems,
although we really should have left them in as a last alternative.) One of
these three rules is selected for firing, and the others are stacked for
backtracking if no rules are newly fireable. This is a standard old-time
conventional AI approach, which is much better addapted to this problem than a
parallel fuzzy system. (Actually, our expert system shell prmits switching from
sequential to parallel modes in mid-run.)

While our syntax is different from the rule in the posting to which you
replied, the above approach accomplishes the same end.

William Siler

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