Table 3: Five different reduct objections.

YearAuthorsReduction objectionReduction function

1982Pawlak [2]Positive region (D) = (D)
1997Miao [4]Mutual information
2000Slezak [5]Distribution (x) = (x)
2001Kryszkiewicz [6]General decision
2009Miao et al. [3]Boundary PartitionIND = IND