@MISC{TIETZE.MIZ,
  AUTHOR = {Korni{\l}owicz, Artur and Bancerek, Grzegorz and Naumowicz, Adam},
  TITLE = {Tietze {E}xtension {T}heorem},
  DAY = {14},
  MONTH = {September},
  YEAR = {2005},
  ADDRESS1 = {University of Bia{\l}ystok, ul. Akademicka 2, 15-267 Bia{\l}ystok},
  ADDRESS2 = {Bia{\l}ystok Technical University},
  ADDRESS3 = {University of Bia{\l}ystok, ul. Akademicka 2, 15-267 Bia{\l}ystok},
  SUMMARY = {In this paper we formalize the Tietze extension theorem using
  as a basis the proof presented at the PlanetMath web server
  (\url{http://planetmath.org/encyclopedia/ProofOfTietzeExtensionTheorem2.html}).}}
