Use of stevens law in product formation

I have to solve problem related fruit yogurt formation with no added sugar. Information about the product is in pictures.

Ingredients: pasteurized and homogenized whole milk, strawberry, sugar, carrageenan, yogurt cultures (S. thermophilus ve L. bulgaricus), citric acid and flavor
A) If use aspartame as a single sweetener, how much aspartame should it be used? What are some important points to consider when aspartame is used in this type of product?
B) How about if a blend of aspartame and saccharin is used? How much of each should be used?
I am not getting what is use of R here and how can i get S, please help me

Aspartame is not a good alternative artificial sweetener due to its effect on phenylketonurics ;plus it’s not heat stable.Regarding dose, in blends with other artificial sweeteners, I don’t speculate as the theoretical of computed amounts based on sweetening power of each material based on empirical or theoretical rule is not accurate as its final judge is sensory evaluation. …

You are right it is not good alternative but I want to know how they get concentration by using stevens law
This question is about using stevens law to find amout and stimulus intensity of sweetners. What is R, and how to use it to find concentration, if i dont know stimulus intėnsity (S) how can i find concentration C .

Steven’s law for me is of academic importance… I did never hear it being mentioned by my colleagues that work in the beverage industry during our regular discussion with product development problems in the food industry in the past and in recent times…