English
The quasi-isomorphism relation commutes with shift by integers via a canonical isomorphism on homology; shifting preserves quasi-isomorphism status.
Русский
Отношение квазиизоморфизма commuting сдвигом на целые через каноническую изоморфию по гомологии; сдвиг сохраняет статус квазиизоморфизма.
LaTeX
$$$\\forall φ, n,\\; \\text{QuasiIso}(φ) \\Rightarrow \\text{QuasiIso}(φ⟦n⟧')$ and conversely$$
Lean4
@[reassoc]
theorem homologySequenceδ_quotient_mapTriangle_obj (T : Triangle (CochainComplex C ℤ)) (n₀ n₁ : ℤ) (h : n₀ + 1 = n₁) :
(homologyFunctor C (up ℤ) 0).homologySequenceδ ((quotient C (up ℤ)).mapTriangle.obj T) n₀ n₁ h =
(homologyFunctorFactors C (up ℤ) n₀).hom.app _ ≫
(HomologicalComplex.homologyFunctor C (up ℤ) 0).shiftMap T.mor₃ n₀ n₁ (by cutsat) ≫
(homologyFunctorFactors C (up ℤ) n₁).inv.app _ :=
by apply homologyFunctor_shiftMap