In this paper, we introduce the notion of multi-fuzzy normed spaces and establish an asymptotic behavior of the quadratic functional equations in the setup of such spaces. We then investigate the superstability of strongly higher derivations in the framework of multi-fuzzy Banach algebras

In this paper, the authors investigate the generalized Ulam-Hyers stability of a Leibniz type additive and quadratic functional equation ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ − − + ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ − + + − + − + − 3 2 3 3 = ) ( ) ( ) ( z y x f t z y x f t z f t y f t x f ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ + − − + ⎟ ⎠ ⎞ ⎜ ⎝ ⎛ − + − + 3 2 3 2 z y x f z y x f in the setting of intuitionistic fuzzy normed spaces using direct and fixed point methods.

s In respect of the de finition of intuitionistic fuzzy n-norm [9] , the definition of generalised intuitionistic fuzzy ψ norm ( in short GIFψN ) is introduced over a linear space and there after a few results on generalized intuitionistic fuzzy ψ normed linear space and finite dimensional generalized intuitionistic fuzzy ψ normed linear space have been developed. Lastly, we have introduced the...

We will review the theory of 2-normed spaces and their structure and we will explain difference of this structure with the normed spaces one. Also, we will introduce a new structure called generalized 2-normed spaces. Mathematics Subject Classification: 46A15, 41A65

A number of semicontinuity concepts and the relations between them are discussed. Characterizations are given for when the (set-valued) metric projection P M onto a proximinal subspace M of a normed linear space X is approximate lower semicontinuous or 2-lower semicontinuous. A geometric characterization is given of those normed linear spaces X such that the metric projection onto every one-dim...

In the present paper, we first introduce different types of fuzzy continuity for mappings between F-normed linear spaces and relations them are investigated. Secondly, principles functional analysis established in context F-spaces. More precisely, based on fact that topological equivalent, obtain closed graph theorem open mapping theorem. Using Zabreiko’s lemma, prove uniform bounded principle ...

In this paper we introduce the notion of weak and strong intuitionistic fuzzy (Schauder) basis on an intuitionistic fuzzy n-normed linear space [5] and prove that an intuitionistic fuzzy n-normed linear space having a weak intuitionistic fuzzy basis is separable. Also we discuss approximation property on the same space. Mathematics Subject Classification: 03B20, 03B52, 46A99, 46H25