English
The dualCoannihilator of a submodule Φ ⊆ M^* is the pullback of Φ's dual annihilator along evaluation.
Русский
dualCoannihilator подмодуля Φ ⊆ M^* — это вытяжка (pullback) дуального аннигилирующего along оценивания.
LaTeX
$$def dualCoannihilator (Φ : Submodule R (Module.Dual R M)) : Submodule R M := Φ.dualAnnihilator.comap (Module.Dual.eval R M)$$
Lean4
/-- The `dualAnnihilator` of a submodule of the dual space pulled back along the evaluation map
`Module.Dual.eval`. -/
def dualCoannihilator (Φ : Submodule R (Module.Dual R M)) : Submodule R M :=
Φ.dualAnnihilator.comap (Module.Dual.eval R M)