∀ {α : Type u_1} [inst : LT α] (motive : (l₁ l₂ : List α) → l₁ < l₂ → Prop) (l₁ l₂ : List α) (h : l₁ < l₂),
  (∀ (h : [] < []), motive [] [] h) →
    (∀ (b : α) (l₂ : List α) (h : [] < b :: l₂), motive [] (b :: l₂) h) →
      (∀ (a : α) (l₁ : List α) (h : a :: l₁ < []), motive (a :: l₁) [] h) →
        (∀ (a : α) (l₁ l₂ : List α) (h : List.Lex (fun x1 x2 => x1 < x2) l₁ l₂), motive (a :: l₁) (a :: l₂) ⋯) →
          (∀ (a : α) (l₁ : List α) (b : α) (l₂ : List α) (h : a < b), motive (a :: l₁) (b :: l₂) ⋯) → motive l₁ l₂ h