exact ⟨by rintro rfl; exact hI.subset_cl, fun h ↦ eq_empty_of_forall_not_mem
  fun x hx ↦ (hI.indep.nonloop_of_mem hx).not_loop (h (hI.subset hx))⟩
case intro
α : Type u_1
ι : Type u_2
M N : Matroid α
I✝ B X X' Y Y' Z R : Set α
n : ℕ∞
e f : α
hX : autoParam (X ⊆ M.E) _auto✝
I : Set α
hI : M.Basis I X
⊢ I = ∅ ↔ X ⊆ M.cl ∅
no goals