Minimum about fuzzy logic
Weighted average analogy

From another aspect we can comprehend singletons centroid computation as standardized weighted average where the situations of singletons values are summation (xi) and then they are multiplicand by corresponding probabilities (yi) as weighted coefficient and the result is normed by weighted coefficient sum ∑ yi – i.e. Sum of all output term verities (combined weight of all „stakes“). Implicit premise is request to verity sum is not-zero. Methods centroid and bisection united area are weighted average generalization.