Volume 32 • Number 3 • 2009   • Bipolar Fuzzy Subalgebras and Bipolar Fuzzy Ideals of BCK/BCI-Algebras Kyoung Ja Lee Abstract. The notion of bipolar fuzzy subalgebras and bipolar fuzzy ideals of a BCK/BCI-algebra is introduced, and several properties are investigated. Relations between a bipolar fuzzy subalgebra and a bipolar fuzzy ideal are given. A condition for bipolar fuzzy subalgebra to be a bipolar fuzzy ideal is provided, and the characterizations of a bipolar fuzzy ideal are stated. The concept of equivalence relations on the family of all bipolar fuzzy ideals of a BCK/BCI-algebra is considered, and some related properties are discussed. 2000 Mathematics Subject Classification: 06F35, 03G25, 08A72. Full text: PDF