“…In the first case, when class is not empty it can serve as a source for rule generation. For instance, if there is "Arrhythmia" class with three properties P1, P2, P3, then it becomes possible to generate the following rule [2]: IF P1 and P2 and P3 THEN Arrhythmia (1) In the second case there are two equivalent classes [2]. For example, there is "Arrhythmia" class and class "A" which is equivalent to class "Arrhythmia".…”