Separation by monotonic functions.
Separation via quadratic functions.
Separation via quadratic functions. (Summary).
Some complex vector systems of partial functional equations
In this paper some types of complex vector systems of partial linear and non-linear functional equations are solved.
Some Functional Inequalities.
Some functional inequalities and their Baire category properties.
Some functional inequalities and their Baire category properties. (Summary).
Stability of an additive-quadratic functional equation of two variables in F-spaces.
Stability of functional inequalities with Cauchy-Jensen additive mappings.
Subadditive functions and partial converses of Minkowski's and Mulholland's inequalities
Let ϕ be an arbitrary bijection of . We prove that if the two-place function is subadditive in then must be a convex homeomorphism of . This is a partial converse of Mulholland’s inequality. Some new properties of subadditive bijections of are also given. We apply the above results to obtain several converses of Minkowski’s inequality.
Subadditive functions on modules and subgroups of abelian groups.
Sur les paires d'équations pré-Schröder et leur équivalence
Pairs of functional pre-Schröder equations (Sₙ) are considered. We show that under some assumptions the system of two equations (S₃), (Sₙ) for some n ≥ 4 is equivalent to the system of all equations (Sₙ) for n ≥ 2. The results answer a question of Gy. Targonski [5] in a particular case.