@MISC{ROUGHS_5.MIZ,
  AUTHOR = {Grabowski, Adam and Sielwiesiuk, Micha{\l}},
  TITLE = {Formalizing Two Generalized Approximation Operators},
  SECTION1 = {Preliminaries},
  SECTION2 = {Generalized Approximation Mappings},
  DAY = {29},
  MONTH = {June},
  YEAR = {2018},
  ADDRESS1 = {Institute of Informatics\\University of Bia{\l}ystok\\Cio\l kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  ADDRESS2 = {Institute of Informatics\\University of Bia{\l}ystok\\Cio\l kowskiego 1M, 15-245 Bia{\l}ystok\\Poland},
  SUMMARY = {Rough sets, developed by Pawlak, are important tool to
  describe situation of incomplete or partially unknown information.
  In this article we give the formal characterization of two
  closely related rough approximations, along the lines proposed in
  a paper by Gomoli{\'n}ska.}}





