Theorem: Matroid.Iso.encard_ground_eq (Matroid/Old/_Equiv.lean)

State before:
α : Type u_1
β : Type u_2
γ : Type u_3
α₁ : Type u_4
α₂ : Type u_5
α₃ : Type u_6
M : Matroid α
N : Matroid β
B I D X Y : Set α
e : M.Iso N
⊢ M.E.encard = N.E.encard
Tactic:
rw [← e.image_ground, e.injOn_ground.encard_image]
State after:
no goals