English
The underlying algebra homomorphism of the codRestrict construction is the same as restricting the underlying algebra homomorphism to p.
Русский
Базовая алгебра-гомоморфизм-конструкция codRestrict совпадает с ограничением исходного гомоморфизма на подполью p.
LaTeX
$$$\text{toAlgHom}(f\ codRestrict p h) = (\text{toAlgHom } f)\ codRestrict p h$$$
Lean4
@[norm_cast]
theorem coe_codRestrict (f : A →A[R] B) (p : Subalgebra R B) (h : ∀ x, f x ∈ p) :
(f.codRestrict p h : A →ₐ[R] p) = (f : A →ₐ[R] B).codRestrict p h :=
rfl