∀ {α : Type u_1} [inst : AddGroup α] (s : AddSubgroup α),
  QuotientAddGroup.quotientRightRelEquivQuotientLeftRel s =
    { toFun := Quotient.map' (fun g => -g) ⋯, invFun := Quotient.map' (fun g => -g) ⋯, left_inv := ⋯, right_inv := ⋯ }