A Complete Algorithm for Attribute Reduction Based on Discernibility Matrix

A complete algorithm for attribute reduction in rough set theory based on discernibility matrix was introduced. The strategy of the algorithm is to select those indispensable condition attributes. If in some iteration the algorithm can not find such attributes it will eliminate one condition attribute preparing for finding indispensable condition attributes in the next iteration. The time complexity of the algorithm in the worst case was analyzed and the proof of its completeness was given. The time complexity of the algorithm is lower than other presented complete algorithms.