1.1. Introducton to Banach Spaces Definition 1.1. Let X be a K–vector space. A functional p ∶ X → [0,+∞) is called a seminorm, if (a) p(λx) = ∣λ∣p(x), ∀λ ∈ K, x ∈X, (b) p(x + y) ≤ p(x) + p(y), ∀x, y ∈X. Definition 1.2. Let p be a seminorm such that p(x) = 0 ⇒ x = 0. Then, p is a norm (denoted by ∥ ⋅ ∥). Definition 1.3. A pair (X, ∥ ⋅ ∥) is called a normed linear space. Lemma 1.4. Each normed sp...

In this paper we introduce the sequence spaces χM (p, q, u), using an modulus function M and defined over a semi normed space (X, q), semi normed by q. We study some properties of these sequence spaces and obtain some inclusion relations.

Let C(X) denote the set of all non-empty closed bounded convex subsets of a normed linear space X. In 1952 Hans R̊adström described how C(X) equipped with the Hausdorff metric could be isometrically embedded in a normed lattice with the order an extension of set inclusion. We call this lattice the R̊adström of X and denote it by R(X). We: (1) outline R̊adström’s construction, (2) examine the struc...

the goal of  this paper is to investigate the solutionand stability in random normed spaces, in non--archimedean spacesand also in $p$--banach spaces and finally the stability using thealternative fixed point of generalized additive functions inseveral variables.