English
There is a MonoidHom Aut A → Aut B given by autMap f, i.e., an algebraic morphism between Aut groups compatible with autMap.
Русский
Существует моноид-гомоморфизм Aut A → Aut B, названный autMap f, совместимый с autMap.
LaTeX
$$$\text{autMapHom } f : Aut A \to Aut B$ is a MonoidHom with $\text{map} = autMap f$ and compatibility.$$
Lean4
@[simp]
theorem autMap_apply_mul {A B : C} [IsConnected A] [IsGalois B] (f : A ⟶ B) (σ τ : Aut A) :
autMap f (σ * τ) = autMap f σ * autMap f τ :=
by
let F := GaloisCategory.getFiberFunctor C
obtain ⟨a⟩ := nonempty_fiber_of_isConnected F A
apply evaluation_aut_injective_of_isConnected F (B : C) (F.map f a)
simp [Aut.Aut_mul_def]