English
The collection of filters on α forms a distributive lattice under the usual join and inf operations.
Русский
Множество фильтров на α образует распределительную решётку по операциям объединения и наименьшего верхнего предела.
LaTeX
$$DistribLattice (Filter α)$$
Lean4
instance : DistribLattice (Filter α) :=
{ Filter.instCompleteLatticeFilter with
le_sup_inf := by
intro x y z s
simp only [and_assoc, mem_inf_iff, mem_sup, exists_imp, and_imp]
rintro hs t₁ ht₁ t₂ ht₂ rfl
exact ⟨t₁, x.sets_of_superset hs inter_subset_left, ht₁, t₂, x.sets_of_superset hs inter_subset_right, ht₂, rfl⟩ }