∀ (x : Substring.Raw) (motive : (∃ l m r, Substring.Raw.ValidFor l m r x) → Prop)
  (x_1 : ∃ l m r, Substring.Raw.ValidFor l m r x),
  (∀ (w w_1 w_2 : List Char) (h : Substring.Raw.ValidFor w w_1 w_2 x), motive ⋯) → motive x_1