∀ {k G : Type u} [inst : CommRing k] [inst_1 : Group G] (A : Rep.{u, u, u} k G) (S : Subgroup G) [inst_2 : S.Normal],
  (groupHomology.H1CoresCoinf A S).X₃ = groupHomology.H1 (A.quotientToCoinvariants S)