English
If hs is algebraic independent, then the image under the inclusion map is also algebraically independent.
Русский
Если hs алгебраически независимо, то образ при включении тоже алгебраически независим.
LaTeX
$$$\text{AlgebraicIndependent}_R \;\text{on } s \Rightarrow \text{AlgebraicIndependent}_R \;\text{on } f''s$$$
Lean4
theorem image {ι} {s : Set ι} {f : ι → A} (hs : AlgebraicIndependent R fun x : s => f x) :
AlgebraicIndependent R fun x : f '' s => (x : A) := by convert AlgebraicIndependent.image_of_comp s f id hs