@ARTICLE { Rsds3693,
author = {Orlowska, Ewa S.}, 
title = {Logical aspects of learning concepts}, 
journal = {International Journal of Approximate Reasoning}, 
number = 	{(no. 4)}, 
volume = 2, 
pages = {349-364}, 
publisher = {Elsevier Science Inc.}, 
address = {Amsterdam, The Netherlands}, 
month = {October}, 
year = 1988, 
issn = {0888-613X}, 
abstract = {This paper is concerned with semantic analysis of learning concepts within the framework of rough set theory. A logic is introduced to express and prove facts about relationships between extensions and intensions of concepts in an incompletely specified universe.}, 
keywords = {information system, incomplete information, acquisition of concepts, rough sets, modal logic, }, 
}