English
A repeated statement that the Galois connection holds between fromIdeal and asIdeal.
Русский
Повторное утверждение существования сопряжения Галуа между fromIdeal и asIdeal.
LaTeX
$$$\mathrm{GaloisConnection}(\mathrm{fromIdeal}, \mathrm{asIdeal})$$$
Lean4
/-- A two-sided ideal is simply a left ideal that is two-sided. -/
@[simps]
def orderIsoIsTwoSided {R : Type*} [Ring R] : TwoSidedIdeal R ≃o { I : Ideal R // I.IsTwoSided }
where
toFun I := ⟨I.asIdeal, inferInstance⟩
invFun
I :=
have := I.2;
I.1.toTwoSided
left_inv _ := by simp
right_inv I := by simp
map_rel_iff' {I I'} := by simp [SetLike.le_def]