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From: anton@mips.complang.tuwien.ac.at (Anton Ertl)
Newsgroups: comp.lang.forth
Subject: Re: Expert systems in forth
Date: Sun, 05 Jan 2025 17:31:10 GMT
Organization: Institut fuer Computersprachen, Technische Universitaet Wien
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melahi_ahmed@yahoo.fr (ahmed) writes:
>On Sun, 5 Jan 2025 15:09:13 +0000, Anton Ertl wrote:
>
>> 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.
>>
>> Potential improvements:
>>
>> 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
>
>
>The bat has wings and can fly and it is a mammal.
>
>
>
>> and egg-laying unless the
>> answer is "don't know" (supporting that would be another improvement).
>
>
>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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