∀ {α : Type u_1} {path : Batteries.RBNode.Path α}
  (motive :
    (path' : Batteries.RBNode.Path α) → (t' : Batteries.RBNode α) → Batteries.RBNode.nil = t' → path = path' → Prop)
  (path' : Batteries.RBNode.Path α) (t' : Batteries.RBNode α) (x : Batteries.RBNode.nil = t') (x_1 : path = path'),
  (∀ (a : Unit), motive path Batteries.RBNode.nil ⋯ ⋯) → motive path' t' x x_1