English
The naturality of the homology component in the isomorphism for left-derived objects holds with additive functors.
Русский
Естественность гомологического компонента в изоморфизме для левого производного сохранена для аддитивных функторов.
LaTeX
$$$\text{hom}_n: (F.mapHomologicalComplex _) \;\to\; \text{HomotopyCategory.homology}(D, n) \text{ is natural in } φ.$$$
Lean4
@[reassoc]
theorem isoLeftDerivedToHomotopyCategoryObj_hom_naturality {X Y : C} (f : X ⟶ Y) (P : ProjectiveResolution X)
(Q : ProjectiveResolution Y) (φ : P.complex ⟶ Q.complex) (comm : φ.f 0 ≫ Q.π.f 0 = P.π.f 0 ≫ f) (F : C ⥤ D)
[F.Additive] :
F.leftDerivedToHomotopyCategory.map f ≫ (Q.isoLeftDerivedToHomotopyCategoryObj F).hom =
(P.isoLeftDerivedToHomotopyCategoryObj F).hom ≫
(F.mapHomologicalComplex _ ⋙ HomotopyCategory.quotient _ _).map φ :=
by
dsimp
rw [← cancel_epi (P.isoLeftDerivedToHomotopyCategoryObj F).inv, Iso.inv_hom_id_assoc,
isoLeftDerivedToHomotopyCategoryObj_inv_naturality_assoc f P Q φ comm F, Iso.inv_hom_id, comp_id]