Hong, Sung Min; Jun, Young Bae; Kim, Seon Jeong; Kim, Gwang Il Fuzzy BCI-subalgebras with interval-valued membership functions. (English) Zbl 0971.06018 Int. J. Math. Math. Sci. 25, No. 2, 135-143 (2001). Summary: The purpose of this paper is to define the notion of an interval-valued fuzzy BCI-subalgebra (briefly, an i-v fuzzy BCI-subalgebra) of a BCI-algebra. Necessary and sufficient conditions for an i-v fuzzy set to be an i-v fuzzy BCI-subalgebra are stated. A way to construct a new i-v fuzzy BCI-subalgebra from an old one is given. The images and inverse images of i-v fuzzy BCI-subalgebras are defined, and it is studied how the images or inverse images of i-v fuzzy BCI-subalgebras become i-v fuzzy BCI-subalgebras. MSC: 06F35 BCK-algebras, BCI-algebras (aspects of ordered structures) 03E72 Theory of fuzzy sets, etc. Keywords:interval-valued fuzzy BCI-subalgebra; BCI-algebra PDF BibTeX XML Cite \textit{S. M. Hong} et al., Int. J. Math. Math. Sci. 25, No. 2, 135--143 (2001; Zbl 0971.06018) Full Text: DOI EuDML