English
For injective g and a compatibility h, AlgebraicIndependent S (g ∘ x) is equivalent to AlgebraicIndependent R x.
Русский
При инъективности g и совместимости h алгебраическая независимость S (g ∘ x) эквивалентна независимости R x.
LaTeX
$$$\\text{Injective}(g) \\Rightarrow (AlgebraicIndependent_S(g \\circ x) \\iff AlgebraicIndependent_R x)$$$
Lean4
theorem algebraicIndependent_ringHom_iff_of_comp_eq (hg : Function.Injective g)
(h : RingHom.comp (algebraMap S B) f = RingHom.comp g (algebraMap R A)) :
AlgebraicIndependent S (g ∘ x) ↔ AlgebraicIndependent R x :=
⟨fun H ↦ H.of_ringHom_of_comp_eq f g (EquivLike.injective f) h, fun H ↦
H.ringHom_of_comp_eq f g (EquivLike.surjective f) hg h⟩