Theorem: Matroid.rFin.er_eq_er_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
hX : M.rFin X
hY : M.rFin Y
⊢ M.er X = M.er Y ↔ M.r X = M.r Y
Tactic:
rw [← hX.coe_r_eq, ← hY.coe_r_eq, Nat.cast_inj]
State after:
no goals