{V : Type u_2} →
  [inst : Quiver V] →
    {X Y : Quiver.Symmetrify V} →
      (motive : (X ⟶ Y) → Sort u_3) →
        (x : X ⟶ Y) → ((g : X ⟶ Y) → motive (Sum.inl g)) → ((g : Y ⟶ X) → motive (Sum.inr g)) → motive x