English
If f is concave on s, then f ∘ g is concave on the preimage of s under a linear map g.
Русский
Если f конкавна на s, то f ∘ g конкавна на прообразе s под линейным отображением g.
LaTeX
$$$\text{If } f \text{ is concave on } s, \text{ then } f\circ g \text{ is concave on } g^{-1}(s)$$$
Lean4
/-- If `f` is concave on `s`, so is `(g ∘ f)` on `g ⁻¹' s` for a linear `g`. -/
theorem comp_linearMap {f : F → β} {s : Set F} (hf : ConcaveOn 𝕜 s f) (g : E →ₗ[𝕜] F) : ConcaveOn 𝕜 (g ⁻¹' s) (f ∘ g) :=
hf.dual.comp_linearMap g