Generalizations of .2; 2_q/-fuzzy subalgebras in BCK/BCI-algebras

More general form of the notion of quasi-coincidence of a fuzzy point with a fuzzy set is considered, and generalizations of results in the papers [Y. B. Jun, On . ; /-fuzzy subalgebras of BCK/BCI-algebras, Bull. Korean Math. Soc. 42 (4) (2005) 703 711; Y. B. Jun, Fuzzy subalgebras of type . ; / in BCK/BCI-algebras, Kyungpook Math. J. 47 (2007) 403 410] are discussed. The notions of .2; qk/-fuzzy subalgebras and .2; 2 _qk/-fuzzy subalgebras in a BCK/BCI-algebra X are introduced, and several properties are investigated. Characterizations of .2; 2_qk/-fuzzy subalgebra in a BCK/BCI-algebra X are discussed.