Rough Sets Mathematical Foundations

From the reviews:

"The textbook ‘Rough Sets – Mathematical Foundations’ of Lech Polkowski intends to give a complete and self-contained exposition of all the relevant material. It covers all essential results in mathematical theory of rough sets and comes with more than 320 carefully selected and commented exercises that give additional hints and background to the reader. Finally it provides a profound reference to the area of mathematical foundations of rough set theory." (Christoph Meinel, Zentralblatt MATH, Vol. 1040 (9), 2004)

"The book starts with an overview of rough sets and a bibliography on rough sets and their applications. … The book is well written. It can serve not only as a monograph, but also as a textbook; it has all the necessary math described inside, and it has over 300 exercises that help the reader master both the math and its applications to rough sets." (V. Ya. Kreinovich, Mathematical Reviews, 2004 e)