Theorem: ENat.isOpen_image_coe (Matroid/ForMathlib/ENatTopology.lean)

State before:
α : Type u_1
β : Type u_2
ι : Type u_3
s✝ : Set α
n : ℕ∞
s : Set ℕ
⊢ IsOpen (Nat.cast '' s)
Tactic:
rw [← openEmbedding_coe.open_iff_image_open]
State after:
α : Type u_1
β : Type u_2
ι : Type u_3
s✝ : Set α
n : ℕ∞
s : Set ℕ
⊢ IsOpen s

State before:
α : Type u_1
β : Type u_2
ι : Type u_3
s✝ : Set α
n : ℕ∞
s : Set ℕ
⊢ IsOpen s
Tactic:
exact trivial
State after:
no goals