∀ {k G : Type u} [inst : CommRing k] [inst_1 : Group G] (A : Rep k G) (x : ↥(groupHomology.cycles₂ A)),
  groupHomology.cyclesMk 2 1 groupHomology.cyclesMk₂_eq._proof_1
      ((CategoryTheory.ConcreteCategory.hom (groupHomology.chainsIso₂ A).inv) ↑x) ⋯ =
    (CategoryTheory.ConcreteCategory.hom (groupHomology.isoCycles₂ A).inv) x