1. A codifying and storing method for membership functions representing a membership degree of fuzzy variables defined within a universe of discourse which is discretized into a finite number of points, comprising: quantizing said membership functions into a finite number of levels corresponding to a finite number of membership degrees, and storing the quantized membership functions according to a characteristic value of each sub-set of values of fuzzy variables which have for their image the same value of said membership degree corresponding to one of said levels.