no goals
α : Type u_1
β : Type ?u.65577
inst✝ : LinearOrder α
a a₁ a₂ b b₁ b₂ c d : α
h₁ : a₁ < b₁
⊢ Ioc a₁ b₁ ⊆ Ioc a₂ b₂ ↔ b₁ ≤ b₂ ∧ a₂ ≤ a₁
convert @Ico_subset_Ico_iff αᵒᵈ _ b₁ b₂ a₁ a₂ h₁ using 2 <;> exact (@dual_Ico α _ _ _).symm