Let s ? 3 $s \geqslant 3$ be a natural number, let ? ( x ) $\psi (x)$ polynomial with real coefficients and degree d 2 $d 2$ , A $A$ some large, non-empty, finite subset of numbers. We use E $E_{s,2}(A)$ to denote the number solutions system equations ? i = 1 ? + 0 \begin{equation*}\hskip2.5pc \sum _{i=1}^{s} (\psi (x_i) - \psi (x_{i+s}) )= (x_i x_{i+s} 0, \end{equation*} where ? $x_i \in A$ fo...

In this article, the concepts of gH-subgradient and gH-subdifferential interval-valued functions are illustrated. Several important characteristics a convex function, e.g., closeness, boundedness, chain rule, etc. studied. Alongside, we prove that gH-differentiable function contains only gH-gradient. It is observed directional gH-derivative maximum all products between gH-subgradients direction...