Re: Expert systems in forth

melahi_ahmed@yahoo.fr (ahmed) writes:

On Sun, 5 Jan 2025 15:09:13 +0000, Anton Ertl wrote:
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melahi_ahmed@yahoo.fr (ahmed) writes:

I'll see how to change the flow of the inference using the action field
of facts and executing them during the inference, like this we can
choose the next rule to use.

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Potential improvements:
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Also have rules that work for both truth and falsness.

Or, more generally, negative rules.  Then there would be:

  bird :- feathers .;
  not bird :- not feathers .;

And then you do not need to ask about wings

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The bat has wings and can fly and it is a mammal.
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and egg-laying unless the
answer is "don't know" (supporting that would be another improvement).

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Your example `platypus', it lays eggs, and it is not a bird.

I am referring to your rule

  bird        :- wings , lay-eggs .;

So if you have established that the animal has wings AND lays eggs
(and is not extinct), it's a bird.  With the negative rules one could
also specify

  not bird :- not wings .;
  not bird :- not lay-eggs .;

Until now, I assume: no equivalent to unknown.
Three level logic: yes/no/unknown (true/false/unknown)can be
implemented.
Perhaps, Carnaugh tables can be helpful.

Strangely, even though there are a lot of people working on logic in
my school, I have never heard of any work in that direction.  But I
would be very surprised if that was uncharted land.

- anton
--
M. Anton Ertl  http://www.complang.tuwien.ac.at/anton/home.html
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