English
The kernel of a homological functor F: C → A is the strictly full triangulated subcategory of objects X such that F.obj(X⟦n⟧) = 0 for all n.
Русский
Ядро гомологического функторa F: C → A — строго полное треангулированное подпорождение, состоящее из объектов X, для которых F.obj(X⟦n⟧) = 0 для всех n.
LaTeX
$$$\\mathrm{homologicalKernel}(F) = \\{X \\in \\mathrm{Obj}(C) : \\forall n, F(X⟦n⟧) = 0\\}$$$
Lean4
/-- The kernel of a homological functor `F : C ⥤ A` is the strictly full
triangulated subcategory consisting of objects `X` such that
for all `n : ℤ`, `F.obj (X⟦n⟧)` is zero. -/
def homologicalKernel : ObjectProperty C := fun X ↦ ∀ (n : ℤ), IsZero (F.obj (X⟦n⟧))