English
The identity functor preserves all limits of all sizes; i.e., PreservesLimitsOfSize (Id_C) for every size.
Русский
Тождественный функтор сохраняет все пределы всех размеров; то есть PreservesLimitsOfSize (Id_C) для любого размера.
LaTeX
$$$$\text{PreservesLimitsOfSize}((\mathrm{Id}_C))\text{ for all sizes.}$$$$
Lean4
instance id_preservesLimitsOfSize : PreservesLimitsOfSize.{w', w} (𝟭 C) where
preservesLimitsOfShape {J}
𝒥 :=
{
preservesLimit := fun {K} =>
⟨fun {c} h =>
⟨fun s => h.lift ⟨s.pt, fun j => s.π.app j, fun _ _ f => s.π.naturality f⟩, by cases K;
rcases c with ⟨_, _, _⟩; intro s j; cases s; exact h.fac _ j, by cases K; rcases c with ⟨_, _, _⟩;
intro s m w; rcases s with ⟨_, _, _⟩; exact h.uniq _ m w⟩⟩ }