EN
Let X be an arbitrary set. Let 𝚽 be a family of real-valued functions defined on X. Let γ:X × X → ℝ. Set [𝚽 + γ] = {Φ(·) + γ(·,x) | Φ ∈ 𝚽, x ∈ X}$. We give conditions guaranteeing the equivalence of $𝚽^{γ(·,·)}$-subdifferentiability and [𝚽 + γ]-subdifferentiability.