English
The inflation map is injective as a morphism of short complexes.
Русский
Инфляционная карта инъективна как морфизм кратких комплексов.
LaTeX
$$$\text{instMonoModuleCatFH1InfRes}$$$
Lean4
/-- The short complex `H¹(G ⧸ S, A^S) ⟶ H¹(G, A) ⟶ H¹(S, A)`. -/
@[simps X₁ X₂ X₃ f g]
noncomputable def H1InfRes : ShortComplex (ModuleCat k)
where
X₁ := groupCohomology (A.quotientToInvariants S) 1
X₂ := groupCohomology A 1
X₃ := groupCohomology ((Action.res _ S.subtype).obj A) 1
f := map (QuotientGroup.mk' S) (subtype _ _ <| le_comap_invariants A.ρ S) 1
g := map S.subtype (𝟙 _) 1
zero := by
rw [← map_comp, Category.comp_id, congr (QuotientGroup.mk'_comp_subtype S) (fun f φ => map f φ 1), map₁_one]