In this paper, as an extension of CI-algebras, we discuss the new notions of Neutro-CI-algebras and Anti-CI-algebras. First, some examples are given to show that these definitions are different. We prove that any proper CI-algebra is a Neutro-BE-algebra or Anti-BE-algebra. Also, we show that any NeutroSelf-distributive and Anti-Commutative CI-algebras are not BE-algebras.

We discuss the interrelations between BCK-algebras and posets with difference. Applications are given to bounded commutative BCK-algebras, difference posets, MV-algebras, quantum MV-algebras and orthoalgebras.

The notions of a hyper MV-deductive system, a -hyper MV-deductive system, a - hyper MV-deductive system, a -hyper MV-deductive system, a -hyper MV-deductive system and a -hyper MV-deductive system are introduced, and then their relations are investigated.

In this paper we introduce the concept of d-fuzzy function which generalizes the concept of fuzzy subalgebra to a much larger class of functions in a natural way. In addition we discuss a method of fuzzification of a wide class of algebraic systems onto [0, 1] along with some consequences.