Computing a T-transitive opening of a proximity

Abstract

A fast method to compute a T-indistinguishability from a reflexive and symmetric fuzzy relation is given for any left-continuous t-norm, taking O(n(3)) time complexity, where n is the number of elements in the universe. It is proved that the computed fuzzy relation is a T-transitive opening when T is the minimum t-norm or a strictly growing t-norm. As far as we know, this is the first known algorithm that computes T-transitive openings preserving the reflexive and symmetric properties.