-Structures Applied to Closed Ideals in BCH-Algebras

The notions of -subalgebras and -closed ideals in BCH-algebras are introduced, and the relation between -subalgebras and -closed ideals is considered. Characterizations of -subalgebras and -closed ideals are provided. Using special subsets, -subalgebras and -closed ideals are constructed. A condition for an -subalgebra to be an -closed ideal is discussed. Given an -structure, the greatest -closed ideal which is contained in the -structure is established.