Theorem: Matroid.rk_map (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
β : Type u_3
M : Matroid α
f : α → β
hf : InjOn f M.E
⊢ (M.map f hf).rk = M.rk
Tactic:
simp [rk]
State after:
no goals