no goals
α : Type u_1
β : Type u_2
inst✝³ : PartialOrder α
inst✝² : PartialOrder β
inst✝¹ : OrderTop α
inst✝ : OrderTop β
f : α ≃o β
⊢ IsCoatomic α ↔ IsCoatomic β
simp only [← isAtomic_dual_iff_isCoatomic, f.dual.isAtomic_iff]