refine ⟨M.cl_subset_cl inter_subset_left, fun i ↦ ?_⟩
ι : Type u_1
α : Type u_2
M : Matroid α
B I J X X' Y Y' F : Set α
Xs Ys Js Is : ι → Set α
i j : ι
e f : α
inst✝ : Nonempty ι
hB : M.ModularBase B Xs
⊢ M.cl ((⋂ i, Xs i) ∩ B) ⊆ M.cl (⋂ i, Xs i) ∧ ∀ (i : ι), M.cl (⋂ i, Xs i) ⊆ M.cl (Xs i ∩ B)
ι : Type u_1
α : Type u_2
M : Matroid α
B I J X X' Y Y' F : Set α
Xs Ys Js Is : ι → Set α
i✝ j : ι
e f : α
inst✝ : Nonempty ι
hB : M.ModularBase B Xs
i : ι
⊢ M.cl (⋂ i, Xs i) ⊆ M.cl (Xs i ∩ B)