@INPROCEEDINGS { Rsds4062,
author = {Radzikowska, Anna Maria}, 
title = {Rough Approximation Operations Based on IF Sets}, 
booktitle = {Artificial Intelligence and Soft Computing - ICAISC 2006}, 
series =  = {Lecture Notes in Artificial Intelligence}, 
volume = 4029, 
pages = {528--537}, 
publisher = {Springer-Verlag}, 
address = {Heidelberg - Berlin, Germany}, 
year = 2006, 
editor = {Rutkowski, Leszek and Tadeusiewicz, Ryszard and Zurada, Jacek M.}, 
issn = {0302-9743}, 
isbn = {978-3-540-35748-3}, 
abstract = {Intuitionistic fuzzy sets, originally introduced by Atanassov, allow for representation both degrees of membership and degrees of nonâ€“membership of an element to a set. In this paper we present a generalisation of Pawlakâ€™s rough approximation operations taking Atanassovâ€™s structures as a basis. A special class of residuated lattices is taken as a basic algebraic structure. In the signature of these algebras we have abstract counterparts of two main classes of fuzzy implications. We show that basing on these lattices we can express degrees of weak and strong certainties and possibilities of membership and nonâ€“membership of an element to a set.}, 
keywords = {rough sets, fuzzy sets, if sets, residuated lattices, fuzzy logical connectives, }, 
}