International Journal of Mathematics and Mathematical Sciences
Volume 25 (2001), Issue 2, Pages 135-143
doi:10.1155/S0161171201005087
Fuzzy BCI-subalgebras with interval-valued membership functions
Sung Min Hong1
, Young Bae Jun2
, Seon Jeong Kim1
and Gwang Il Kim1
1Department of Mathematics, Gyeongsang National University, Chinju 660-701, South Korea
2Department of Mathematics Education, Gyeongsang National University, Chinju 660-701, South Korea
Abstract
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 make a new i-v fuzzy BCI-subalgebra from old one is given. The images and inverse images of i-v fuzzy BCI-subalgebras are defined, and how the images or inverse images of i-v fuzzy BCI-subalgebras become i-v fuzzy BCI-subalgebras is studied.