METHOD FOR CALCULATE THE NUMBER OF UNREAD PEOPLE IN A GROUP CHAT MESSAGE AND RECORDING MEDIUM STORING PROGRAM FOR EXECUTING THE SAME AND RECORDING MEDIUM STORING PROGRAM FOR EXECUTING THE SAME

摘要

The present invention relates to a method for calculating the number of people who do not read a group chat message which obtains the number of participants (u_m (m is a natural number)) who do not read an m^th message with respect to an index on which an order of the last message ready by a participant is displayed.