rw [disjoint_iff_inter_eq_empty, ← inter_diff_right_comm, diff_eq_empty]
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
h : M.Skew X Y
⊢ Disjoint (X \ M.cl ∅) Y
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
h : M.Skew X Y
⊢ X ∩ Y ⊆ M.cl ∅