The concept of quasi-coincidence of an interval valued fuzzy set is considered. By using this idea, the notion of interval valued (α, β)−fuzzy sub-implicative ideals of BCIalgebras is introduced, which is a generalization of a fuzzy sub-implicative ideal. Also some related properties are studied and in particular, the interval valued (∈,∈ ∨q)−fuzzy subimplicative ideals in a BCI-algebra will be...

The aim of this paper is to apply the concept of interval-valued intuitionistic fuzzy set to implicative ideals and commutative ideals in BCK-algebras and introduced the new notion of interval-valued intuitionistic fuzzy implicative ideals in BCK-algebras and interval-valued intuitionistic fuzzy commutative ideals in BCK-algebras and related properties are investigated.

The class of radial fuzzy systems is introduced. The fuzzy systems in this class use radial functions to implement membership functions of fuzzy sets and exhibit a shape preservation property in antecedents of their rules. The property is called the radial property. It enables the radial fuzzy systems to have their computational model mathematically tractable under both conjunctive and implicat...

We consider the fuzzification of the notion of an n-fold implicative ideal, an n-fold (weak) commutative ideal. We give characterizations of an n-fold fuzzy implicative ideal. We establish an extension property for n-fold fuzzy commutative ideals. 2000 Mathematics Subject Classification. 06F35, 03G25, 03E72.

This paper presents two classes of propositional logics (understood as a consequence relation). First we generalize the well-known class of implicative logics of Rasiowa and introduce the class of weakly implicative logics. This class is broad enough to contain many “usual” logics, yet easily manageable with nice logical properties. Then we introduce its subclass— the class of weakly implicativ...

In this contribution, an implicative variant of the conjunctive normal form will be recalled and further studied. This normal form is an alternative to the Perfilieva’s conjunctive normal form. It will be shown that it is a suitable model for a particular case of graded fuzzy rules introduced as a generalization of classical fuzzy rules. Moreover, approximation properties of the implicative var...

This study focuses on combining the theories of m -polar fuzzy sets over id="M2"> BCK -algebras and establishing a new framework id="M3"> id="M4"> -algebras. In this paper, we define idea id="M5"> positive implicative ideals in id="M6"> investigate some related properties. Then, introduce concepts id="M7">...

A generalization of an (∈, ∈ ∨ q)-fuzzy bi-filter (resp. (∈, ∈ ∨ q)fuzzy bi-filter) of an ordered semigroup is discussed. Characterizations of an (∈, ∈ ∨ qk)-fuzzy bi-filter and an (∈, ∈ ∨ qk)-fuzzy bi-filter are provided. Relations between fuzzy bi-filters and (∈, ∈ ∨ qk)-fuzzy bifilters (resp. (∈, ∈ ∨ qk)-fuzzy bi-filters) are described. Conditions for an (∈, ∈∨ qk)-fuzzy bi-filter (resp. (∈,...

In this paper, we introduce the concepts of fuzzy ideals, fuzzy implicative ideals and fuzzy p-ideals in BF-algebras and investigate some of its properties.