Complements on left homology map data #
Two facts about ShortComplex.LeftHomologyMapData: the compatibility commf' follows from the
compatibility commi (LeftHomologyMapData.commf'_of_commi), and a variant of
LeftHomologyMapData.homologyMap_comm where the left homology objects are replaced by isomorphic
objects (LeftHomologyMapData.homologyMap_comp_homologyIso_trans_hom).
theorem
CategoryTheory.ShortComplex.LeftHomologyMapData.commf'_of_commi
{C : Type u_1}
[Category.{v_1, u_1} C]
[Limits.HasZeroMorphisms C]
{S₁ S₂ : ShortComplex C}
{φ : S₁ ⟶ S₂}
(h₁ : S₁.LeftHomologyData)
(h₂ : S₂.LeftHomologyData)
{φK : h₁.K ⟶ h₂.K}
(commi : CategoryStruct.comp φK h₂.i = CategoryStruct.comp h₁.i φ.τ₂)
:
The compatibility commf' of a left homology map data follows from the compatibility
commi.
theorem
CategoryTheory.ShortComplex.LeftHomologyMapData.homologyMap_comp_homologyIso_trans_hom
{C : Type u_1}
[Category.{v_1, u_1} C]
[Limits.HasZeroMorphisms C]
{S₁ S₂ : ShortComplex C}
[S₁.HasHomology]
[S₂.HasHomology]
{φ : S₁ ⟶ S₂}
{h₁ : S₁.LeftHomologyData}
{h₂ : S₂.LeftHomologyData}
(γ : LeftHomologyMapData φ h₁ h₂)
{A₁ A₂ : C}
(e₁ : A₁ ≅ h₁.H)
(e₂ : A₂ ≅ h₂.H)
(g : A₁ ⟶ A₂)
(hg : CategoryStruct.comp e₁.hom γ.φH = CategoryStruct.comp g e₂.hom)
:
CategoryStruct.comp (homologyMap φ) (h₂.homologyIso ≪≫ e₂.symm).hom = CategoryStruct.comp (h₁.homologyIso ≪≫ e₁.symm).hom g
A variant of LeftHomologyMapData.homologyMap_comm where the left homology objects are
replaced by isomorphic objects.