English
The quotient by the dual equals the dual annihilator via a natural equivalence.
Русский
Картезиев переход: квотирование по дуалу дает дуальный аннигилятор через естественное соответствие.
LaTeX
$$quotDualEquivAnnihilator (W) : (Module.Dual K V ⧸ LinearMap.range W.dualLift) ≃ₗ[K] W.dualAnnihilator$$
Lean4
/-- The quotient by the dual is isomorphic to its dual annihilator. -/
noncomputable def quotDualEquivAnnihilator (W : Subspace K V) :
(Module.Dual K V ⧸ LinearMap.range W.dualLift) ≃ₗ[K] W.dualAnnihilator :=
LinearEquiv.quotEquivOfQuotEquiv <| LinearEquiv.trans W.quotAnnihilatorEquiv W.dualEquivDual