English
The homOf construction is compatible with the underlying hom complex as a morphism.
Русский
Конструкция homOf совместима с соответствующим гомоморфизмом в гом-комплексе.
LaTeX
$$homOf (z) : F ⟶ G is a morphism and preserves the cocycle structure$$
Lean4
/-- The morphism in `CochainComplex C ℤ` associated to a `0`-cocycle. -/
@[simps]
def homOf (z : Cocycle F G 0) : F ⟶ G
where
f i := (z : Cochain _ _ _).v i i (add_zero i)
comm' := by
rintro i j rfl
rcases z with ⟨z, hz⟩
dsimp
rw [mem_iff 0 1 (zero_add 1)] at hz
simpa only [δ_zero_cochain_v, Cochain.zero_v, sub_eq_zero] using Cochain.congr_v hz i (i + 1) rfl