I refuse to get drawn into a discussion on this matter. But let me say that
these four rules, posted by Will, come from an actual product pricing model
which contained about 120 rules. I even state this in my book. Not only does
this model work, but it has been used to successfully price and re-price
several million dollars worth of materiel and demographically sensitive
products for many years.

The fact that you would throw out the first two rules -- what are not
"obvious problems"  indicates that you have no conception whatever about the
actual mechanics of fuzzy systems. Since fuzzy logic does not obey the Law
of Excluded Middle these two rules form a fuzzy constraint on the possible
solution set (the conjunction of Tall and Not Tall is not an empty set and
if you don't know why this is so, you definitely shouldn't even THINK about
discussing fuzzy logic in this forum).

earl cox


"Radford Neal" <radford@cs.toronto.edu> wrote in message
news:2001Aug3.143317.1085@jarvis.cs.toronto.edu...

> In article <3B6AE135.5040104@bellatlantic.net>, > <predictr@bellatlantic.net> wrote: > >> Here is a simple fuzzy logic system, borrowed from an example given in >> "The Fuzzy Systems Handbook", by Earl Cox. The problem is to establish >> the price of a product. The fuzzy system has 4 rules: >> >> 1. The price should be high >> 2. The price must be low >> 3. The price must be around 2 times cost >> 4. If the competition price is not very high, then the price should be >> near the competition price >> >> Mathematical definitions terms like "high", "low", "near the competition >> price" etc. are part of this fuzzy system, which yields a suggested >> price. These rules are in fact part of a system which has been used to >> price millions of dollars worth of real products for a profit-making >> enterprise. This fuzzy system solves the problem for which it was

intended.

>> >> My question to fuzzy critics is: why should this system not be used? > > Because it's obvious that any connection between the price arrived at > using the above "rules" and the price that maximizes the firm's profit > is purely coincidental. > > I'm particularly amused by the conjunction of (1) and (2), but beyond > such obvious problems, the fact that these rules lack any substantial > connection to such crucial factors as the price elasticity of demand > and the cost of production of competing producers shows how ridiculous > they are. > > I strongly doubt that any successful firm seriously uses such a system > to price their products. > > Radford Neal