1. A computer implemented method of rearranging a plurality of fuzzy reasoning rules stored in a first memory area of said computer, each of the rules comprising an antecedent, including at least one antecedent proposition, and a consequent, said method comprising the steps of: (a) extracting an antecedent proposition, from said rules stored in said first memory area, which has the highest frequency of appearance in said rules stored in said first memory area, and forming one group of rules consisting of those rules stored in said first memory area which have the extracted antecedent proposition in common; (b) if said one group of rules contains a rule in which an antecedent has only the extracted antecedent proposition, storing that rule in a second memory area of said computer, and excluding that rule from said one group of rules; (c) extracting an antecedent proposition having the next highest frequency of appearance from among the rules remaining in said one group of rules, and forming a sub-group of rules consisting of rules which have said extracted antecedent proposition having the next highest frequency of appearance in common; (d) storing the rules in the second memory area in an order of common antecedent propositions having the highest frequency of appearance and in an order in which the common antecedent propositions are included in larger proportion, by repeating the processing of said steps (b) and (c) with regard to said sub-group of rules; and (e) after the processing of said steps (a) through (d) has been completed with respect to said one group of rules, repeating the processing of said steps (a) through (d) on the remaining rules stored in said first memory, from which the rules contained in said one group of rules have been eliminated, until all rules stored in said first memory area are eliminated.