@MISC{ROUGHS_1.MIZ,
  AUTHOR = {Grabowski, Adam},
  TITLE = {Basic Properties of Rough Sets and Rough Membership Function},
  NOTE = {This work has been partially supported by the CALCULEMUS
      grant HPRN-CT-2000-00102.},
  SECTION1 = {Preliminaries},
  SECTION2 = {Tolerance and Approximation Spaces},
  SECTION3 = {Membership Function},
  SECTION4 = {Rough Inclusion},
  SECTION5 = {Rough Equality of Sets},
  DAY = {23},
  MONTH = {November},
  YEAR = {2003},
  ADDRESS1 = {University of Bia{\l}ystok},
  SUMMARY = {We present basic concepts concerning rough set theory.
  We define tolerance and approximation spaces and rough membership
  function. Different rough inclusions as well as the predicate of
  rough equality of sets are also introduced.}}

