PURPOSE: To eliminate descriptions which are not essential to the condition part of a rule and to shorten the time for collation by dividing the rule into groups at the time of collating the condition part of the rule in a rule base with an element in a short term storage region.

CONSTITUTION: When the change information of the short term storage region is sent from a route node 1, a user information memory A23 or B25 is investigated and when the rule group is used, the information is immediately sent to a discriminating network A27 or B28. Based on this information, the condition part of the rule is collated with the element of the storage region, and the information of these rules is sent to a competition set management 3. On the other hand, in the case of the unused rule group, the change information is stored in a local memory A24 or B26 and when use is started, the contents of a use information memory A23 or B25 are reloaded during the use. Then, the stored change information is successively sent to the discriminating network A27 or B28. Oppositely, when the use is stopped, the contents of the use information memories A23 and B25 are reloaded into the unused state.