Theorem: Matroid.r_eq_of_er_eq (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
h : M.er X = M.er Y
⊢ M.r X = M.r Y
Tactic:
rw [r, r, h]
State after:
no goals