English
The additive equivalence homAddEquiv is compatible with the underlying coe; it preserves addition via the hom-equivalence to ShiftedHom.
Русский
Аддитивная эквивалентность homAddEquiv совместима с базовым отображением; она сохраняет сложение через эквивалентность гом к ShiftedHom.
LaTeX
$$$\\mathrm{homAddEquiv} : Ext(X,Y,n) \\to_+ ShiftedHom(...)$ and its coherence with addition$$
Lean4
/-- When an instance of `[HasDerivedCategory.{w'} C]` is available, this is the additive
bijection between `Ext.{w} X Y n` and a type of morphisms in the derived category. -/
noncomputable def homAddEquiv {n : ℕ} :
Ext.{w} X Y n ≃+ ShiftedHom ((singleFunctor C 0).obj X) ((singleFunctor C 0).obj Y) (n : ℤ)
where
toEquiv := homEquiv
map_add' := by simp