Generating indistinguishability operators from prototypes

Given a T‐indistinguishability operator E defined between some fuzzy subsets of a universe of discourse X, this paper studies three ways to generate an indistinguishability operator on X compatible with E inspired by the tools used in approximate reasoning and on the duality principle. Of special interest are the cases when the fuzzy subsets determine a partition and a hard‐partition of the universe X. © 2002 Wiley Periodicals, Inc.