Filters of Sheffer Stroke BL-Algebras Associated With a New Type of Fuzzy Set and Fuzzy Points

(Ultra) filters in Sheffer stroke BL-algebras based on the Jun’s JδY-fuzzy set are studied. The concept of (ultra) (∈, ∈)-JδY-fuzzy filters in Sheffer stroke BL-algebras is introduced, and various fundamental properties are investigated. Characterizations of (∈, ∈)-JδY-fuzzy filters are discussed, and the relationship between the fuzzy filter and the (∈, ∈)-JδY-fuzzy filter is considered. The conditions for the (∈, ∈)-JδY-fuzzy filter to become ultra are explored.