The Theory of Falling Shadows Applied to -Ideals in -Algebras

On the basis of the theory of a falling shadow which was first formulated by Wang (1985), the notion of falling ∗-ideals in -algebras is introduced, and related properties are investigated. Characterizations of a falling ∗-ideal are established. Relations among falling ∗-ideals, falling -ideals, falling #-ideals, falling -subalgebras, and falling BCK-ideals are discussed