In reply to the follow statement by Herman Rubin,>> In any truth-value system, the truth of a statement made >> by combining other statements with logical operators >> depends only on the truth-values and the operators. The >> truth-value of A OR B depends ONLY on those of A and B. >> If A has truth-value 1/2, and B has truth-value 1/2, the >> truth-value of A OR B is the same if B=A or if B = ~A.
"Earl Cox" <earldcox1@home.com> wrote:> You picked the middle point of a fuzzy continuum to comment on this truth > equivalence. This point is not only a rare occurrence in a real fuzzy system > but is simply a special case where the truth values just happen to be > equivalent. [...] But you are right, a fuzzy system is truth-value based. > There is absolutely nothing wrong with this.
If fuzzy logic breaks down on elementary examples, what will happen in complex problems? Consider the mayor of Ashtabula. Let A = "mayor's right eye is blue". Let B = "mayor's left eye is blue". Let B' = "mayor's left eye is brown". What do you suppose is the truth value of A B ? What about A B' ? The difficulty is that rules of the kind applied in fuzzy logic ignore relations between the elements of a compound proposition. Incidentally, some people do have eyes of different colors. For all I know the mayor of Ashtabula is one of them. Regards, Robert Dodier -- "Nature exists once only" -- Ernst Mach