Theorem: Matroid.r_eq_zero_iff (Matroid/Rank.lean)

State before:
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
inst✝ : M.FiniteRk
hX : X ⊆ M.E
⊢ M.r X = 0 ↔ X ⊆ M.cl ∅
Tactic:
rw [← er_eq_coe_iff, coe_zero, er_eq_zero_iff]
State after:
no goals