∀ {α : Type u_1} {n : ℕ} (motive : (x x_1 : Vector α n) → x.toArray = x_1.toArray → Prop) (x x_1 : Vector α n)
  (x_2 : x.toArray = x_1.toArray),
  (∀ (toArray : Array α) (size_toArray : toArray.size = n),
      motive (Vector.mk toArray size_toArray) (Vector.mk toArray ⋯) ⋯) →
    motive x x_1 x_2