English
The infimum (intersection) of two I-filtrations is an I-filtration with N-component equal to the infimum of the two N-components: (F ⊓ F').N = F.N ⊓ F'.N.
Русский
Пересечение двух I-фильтраций есть I-фильтрация; компонент N равен пересечению: (F ⊓ F').N = F.N ⊓ F'.N.
LaTeX
$$(F ⊓ F').N = F.N ⊓ F'.N$$
Lean4
/-- The `inf` of two `I.Filtration`s is an `I.Filtration`. -/
instance : Min (I.Filtration M) :=
⟨fun F F' =>
⟨F.N ⊓ F'.N, fun i => inf_le_inf (F.mono i) (F'.mono i), fun i =>
(smul_inf_le _ _ _).trans <| inf_le_inf (F.smul_le i) (F'.smul_le i)⟩⟩