rw [disjoint_iff_forall_ne]
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.SkewFamily Xs
hI : M.Indep I
hij : i ≠ j
⊢ Disjoint (Xs i ∩ I) (Xs j)
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.SkewFamily Xs
hI : M.Indep I
hij : i ≠ j
⊢ ∀ ⦃a : α⦄, a ∈ Xs i ∩ I → ∀ ⦃b : α⦄, b ∈ Xs j → a ≠ b