Affiliations: Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Banacha 2, 02-097 Warszawa, Poland. piotr@mimuw.edu.pl
Correspondence:
[*]
Address for correspondence: University of Warsaw, Banacha 2, 02-097 Warszawa, Poland. The research presented at this paper has been supported by the research grant 2011/01/D/ST6/06981 from the Polish National Science Centre and by the research project from the Homing Plus programme, Edition 3/2011, of the Foundation for Polish Science, co-financed from the European Union Regional Development Fund.
Abstract: The paper is aimed at comparing Rough Set Theory (RST) and Formal Concept Analysis (FCA) with respect to algebraic structures of concepts appearing in both theories, namely algebras of definable sets and concept lattices. The paper presents also basic ideas and concepts of RST and FCA together with some set theoretical concepts connected with set spaces which can serve as a convenient platform for a comparison of RST and FCA. In the last section there are shown necessary and sufficient conditions for the fact, that families of definable sets and concept extents determined by the same formal contexts are equal . This in finite cases is equivalent to an isomorphism of respective structures and generally reflects a very specific situation when both theories give the same conceptual hierarchies.
