“…In particular, in [7][8][9], the convexity property was effectively applied toward solving existence problems for both functional-difference inclusions and kinetic equations of statistical physics. It proved to be especially fruitful for the theory of nonlinear differential-operator equations [10][11][12], control theory, and optimization theory [13,14]. Some interesting and important local convexity properties, relevant to mappings of Hilbert spaces, were initially discussed in [3], and later generalized and studied in [15][16][17], devoted to the closedness of quadratic mappings on a separable Hilbert space.…”