English
The locally small full subcategory of Ind-objects is well-behaved (exists hom-sets).
Русский
Локально малая полноть подкатегории Ind-объектов корректна (множества гомоморфизмов существуют).
LaTeX
$$$\mathrm{LocallySmall}\big(\mathrm{ObjectProperty.FullSubcategory}(\mathrm{IsIndObject}(C))\big)$$$
Lean4
/-- Implementation; see `nonempty_indParallelPairPresentation`. -/
def ϕ : F₁ f g P₁ P₂ ⟶ F₂ f g P₁ P₂ where
app h := h.hom.1.left
naturality _ _
h := by
have := h.w
simp only [Functor.prod'_obj, Functor.comp_obj, prod_Hom, Functor.prod'_map, Functor.comp_map, prod_comp,
Prod.mk.injEq, CostructuredArrow.hom_eq_iff, CostructuredArrow.map_obj_left,
IndObjectPresentation.toCostructuredArrow_obj_left, CostructuredArrow.comp_left, CostructuredArrow.map_map_left,
IndObjectPresentation.toCostructuredArrow_map_left] at this
exact this.1