>>> John Boone on logic
JB> I will begin by quoting part of it:
JB> The notions of fuzzy set A and B, A or B can be used for
JB> multi valued propositional calculus. To wit: p, q the
JB> true values of P, Q, 0<=p,q<=1. Truth value of not P
JB> is 1-p, of P&Q is min(p,q), or P or Q is max(p,q). Note
JB> that P or Q equivalent not(notP and notQ) and P&Q
JB> equivalent not(notP or notQ). So does it fly?
JB> Where to? Can we take P implies Q, P->Q, to be
JB> not(P & notQ) or equivalent notP or Q?
JB> According to Kahane's book, the logic of P implies Q,
P -> Q is (P&Q)&(P¬Q). I wonder if this would change
JB> the truth values given for P -> Q. I have not checked
JB> this but thought I would write and see what you get.
This cannot be so as (P&Q)&(P¬Q) is in itself a contradiction. The two
value true tables do check out for A -) B as indicated above. As for the
probalistic values, I recall checking them out for A or B = not (not A & not
B) and it's duel A and B = not (not A or not B).
Indeed 1 - min(A, 1-B) = max (1-A, B), and as I recall I worked the truth
tables for A -) B for three values to show you the problem with that approach
regarding equivalence. Namely for certain truth values of A and B, A
equivalent B even tho A and B have different truth values. This is where it
doesn't fly conceptually.
---
---------------
* Origin: Sunken R'lyeh - Aloha, OR (503) 642-3548 (1:105/337)
|