# Re: is fuzzy logic?

Subject: Re: is fuzzy logic?
From: Thomas Whalen (whalen@gsu.edu)
Date: Tue Feb 08 2000 - 23:18:21 MET

The phrase "fuzzy logic" has a broad and a narrow meaning.
In the narrow sense, it's not fuzzy logic unless it uses
fuzzy extensions of the operations of ordinary logic, which
generally means If-Then along with some others -- in other
words, rules.

But fuzzy logic in the broad sense includes a myriad of other
things that revolve around fuzzy sets and membership functions.
A major part of it is fuzzy arithmetic, which seems to describe

nic wrote:
>
> I've this problem. In fuzzy logic is obligatory to define rules or not?
> I mean, I've 4 input with different membership function. I've a formula
> a*b*c/d. Well I can use rules to have the same result of the formula, but
> I've to write too much (4 input 3 level of membership function: 7,5,3
> Member. and 5 output !!!).
> May I use the multiply formula, get an output and defuzzif. (using cog
> method)? Is it a Fuzzy method? Better does this method belongs to Fuzzy
> logic or I do a middle way?
> And... how can I do with the degree of membership? I found formula only for
> input: triang. (a,b,c)*(d,e,f)=(a*d,b*e,c*f). I think to use the same method
> of the rules (the minumum of degree of membership) but I don't know if it's
> right.
> Thanks a lot.
> Nicola Berti
> nicolab@ftbcc.it
>
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```--
Tom Whalen     whalen@gsu.edu  http://www.gsu.edu/~dscthw
Professor of Decision Science
The Georgia State University         "First things first, but not
Atlanta, GA 30303-3083 USA         necessarily in that order"  - Dr. Who
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```

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