English
The extensionality lemma for AlgHoms from RingQuot via mkAlgHom.
Русский
Лемма экстенсиональности для AlgHom из RingQuot через mkAlgHom.
LaTeX
$$$\\text{ringQuot_ext'}$ — Extensionality for AlgHom via mkAlgHom。$$
Lean4
@[ext 1100]
theorem ringQuot_ext' {s : A → A → Prop} (f g : RingQuot s →ₐ[S] B)
(w : f.comp (mkAlgHom S s) = g.comp (mkAlgHom S s)) : f = g :=
by
ext x
rcases mkAlgHom_surjective S s x with ⟨x, rfl⟩
exact AlgHom.congr_fun w x