@MISC{PZFMISC1.MIZ,
  AUTHOR = {Korni{\l}owicz, Artur},
  TITLE = {Some Basic Properties of Many Sorted Sets},
  SECTION1 = {Preliminaries},
  SECTION2 = {Singleton and unordered pairs},
  SECTION3 = {Sum of unordered pairs (or a singleton) and a set},
  SECTION4 = {Intersection of unordered pairs (or a singleton) and a set},
  SECTION5 = {Difference of unordered pairs (or a singleton) and a set},
  SECTION6 = {Cartesian product},
  DAY = {29},
  MONTH = {September},
  YEAR = {1995},
  ADDRESS1 = {Institute of Mathematics\\Warsaw University\\Bia{\l}ystok}}

