RT Journal Article T1 Computing a T-transitive lower approximation or opening of a proximity relation A1 Garmendia Salvador, Luis A1 Salvador Alcaide, Adela A1 Montero De Juan, Francisco Javier AB Since transitivity is quite often violated even by decision makers that accept transitivity in their preferences as a condition for consistency, a standard approach to deal with intransitive preference elicitations is the search for a close enough transitive preference relation, assuming that such a violation is mainly due to decision maker estimation errors. In some way, the higher the number of elicitations, the more probable is inconsistency. This is mostly the case within a fuzzy framework, even when the number of alternatives or objects to be classified is relatively small. In this paper, we propose a fast method to compute a T-indistinguishability from a reflexive and symmetric fuzzy relation, T being any left-continuous t-norm. The computed approximation we propose will have O(n3) time complexity, where n is the number of elements under consideration, and is expected to produce a T-transitive opening. To the authors’ knowledge, there is no other proposed algorithm that computes T-transitive lower approximations or openings while preserving the reflexivity and symmetry properties. PB Elsevier Science Bv SN 0165-0114 YR 2009 FD 2009 LK https://hdl.handle.net/20.500.14352/50075 UL https://hdl.handle.net/20.500.14352/50075 LA eng NO Garmendia, L., Salvador, A., Montero, J.: Computing a T-transitive lower approximation or opening of a proximity relation. Fuzzy Sets and Systems. 160, 2097-2105 (2009). https://doi.org/10.1016/j.fss.2009.01.015 DS Docta Complutense RD 6 abr 2025