intro (_ : m₁ ≃ m₂) (_ : n ≤ m₁)
ℕ : Type
inst✝³ : Core ℕ
inst✝² : Induction ℕ
inst✝¹ : Addition ℕ
inst✝ : Sign ℕ
order_inst : Order ℕ
n m₁ m₂ : ℕ
⊢ m₁ ≃ m₂ → n ≤ m₁ → n ≤ m₂
ℕ : Type
inst✝³ : Core ℕ
inst✝² : Induction ℕ
inst✝¹ : Addition ℕ
inst✝ : Sign ℕ
order_inst : Order ℕ
n m₁ m₂ : ℕ
x✝¹ : m₁ ≃ m₂
x✝ : n ≤ m₁
⊢ n ≤ m₂