@INPROCEEDINGS { Rsds2542,
author = {Maluszynski, Jan and Damasio, Carlos Viegas and Vitoria, Aida}, 
title = {Query Answering in Rough Knowledge Bases}, 
booktitle = {RSFDGrC}, 
series =  = {Lecture Notes in Artificial Intelligence}, 
volume = 2639, 
pages = {197--204}, 
publisher = {Springer-Verlag}, 
address = {Heidelberg - Berlin, Germany}, 
month = {May}, 
year = 2003, 
editor = {Wang, Guoying and Liu, Quing and Yao, Yiyu and Skowron, Andrzej}, 
issn = {0302-9743}, 
isbn = {3-540-14040-9}, 
abstract = {We propose a logic programming language which makes it possible to define and to reason about rough sets. In particular we show how to test for rough inclusion and rough equality. This extension to our previous work [7] is motivated by the need of these concepts in practical applications.}, 
keywords = {rough sets, logic programming, stable models, uncertain reasoning, }, 
}