@MISC{CLOSURE1.MIZ,
  AUTHOR = {Korni{\l}owicz, Artur},
  TITLE = {On the Many Sorted Closure Operator
and the Many Sorted Closure System},
  SECTION1 = {Preliminaries},
  SECTION2 = {Properties of Many Sorted Closure Operators},
  SECTION3 = {On the Many Sorted Closure Operator and the Many Sorted Closure System},
  DAY = {07},
  MONTH = {February},
  YEAR = {1996},
  ADDRESS1 = {Institute of Mathematics
Warsaw University\\Bia{\l}ystok}}

