English
If f is strictly concave on s, then f + constant is strictly concave on s.
Русский
Если f строго вогнутая на s, то f + константа строго вогнутая на s.
LaTeX
$$$\text{If } f\text{ is strictly concave on } s,\; f+ c\text{ is strictly concave on } s$$$
Lean4
theorem add_const {γ : Type*} {f : E → γ} [AddCommMonoid γ] [PartialOrder γ] [IsOrderedCancelAddMonoid γ] [Module 𝕜 γ]
(hf : StrictConcaveOn 𝕜 s f) (b : γ) : StrictConcaveOn 𝕜 s (f + fun _ => b) :=
hf.add_concaveOn (concaveOn_const _ hf.1)