English
The EffectiveEpiFamily structure admits a unique desc morphism: if m satisfies π a ≫ m = e a for all a, then m equals the desc map.
Русский
Структура EffectiveEpiFamily допускает уникальный morphism-desc: если для всех a выполняется π a ≫ m = e a, то m равно соответствующей desc.
LaTeX
$$m = EffectiveEpiFamily.desc X π e h$$
Lean4
theorem uniq {B W : C} {α : Type*} (X : α → C) (π : (a : α) → (X a ⟶ B)) [EffectiveEpiFamily X π]
(e : (a : α) → (X a ⟶ W))
(h : ∀ {Z : C} (a₁ a₂ : α) (g₁ : Z ⟶ X a₁) (g₂ : Z ⟶ X a₂), g₁ ≫ π _ = g₂ ≫ π _ → g₁ ≫ e _ = g₂ ≫ e _) (m : B ⟶ W)
(hm : ∀ a, π a ≫ m = e a) : m = EffectiveEpiFamily.desc X π e h :=
(EffectiveEpiFamily.getStruct X π).uniq e h m hm