{α : Type u_2} →
  {β : Type u_1} →
    (motive : (Option β × Std.DHashMap.Raw α fun x => β) → Sort u_3) →
      (x : Option β × Std.DHashMap.Raw α fun x => β) →
        ((previous : Option β) → (r : Std.DHashMap.Raw α fun x => β) → motive (previous, r)) → motive x