Ein Beitrag zur Baire-Kategorie-Theorie.
Eine Charakterisierung der multiplikativen Gruppe eines Körpers.
Eine Charakterisierung der positiv definiten quadratischen Formen.
Einige Bemerkungen über eine Differenzenfunktionalgleichung.
Equations fonctionnelles et recherche de sous-groupes.
Équations fonctionnelles liées aux groupes linéaires commutatifs
Equations of the form H(x...y) = ...fi(x)gi(y).
Equivalence of 'Cube' and 'Octahedron' Functional Equations.
Espacios de producto interno (II).
Among normal linear spaces, the inner product spaces (i.p.s.) are particularly interesting. Many characterizations of i.p.s. among linear spaces are known using various functional equations. Three functional equations characterizations of i.p.s. are based on the Frchet condition, the Jordan and von Neumann identity and the Ptolemaic inequality respectively. The object of this paper is to solve generalizations of these functional equations.
Euler-Lagrange type cubic operators and their norms on space.
Existence and uniqueness of solutions of non-linear functional equations of r-th order
Extension of additive functionals and semicharacters on commutative semigroups.