{α : Type u_2} →
  {β : Type u_1} →
    {x : BEq α} →
      {x_1 : Hashable α} →
        (motive : (Option β × Std.DHashMap α fun x => β) → Sort u_3) →
          (x_2 : Option β × Std.DHashMap α fun x => β) →
            ((previous : Option β) → (r : Std.DHashMap α fun x => β) → motive (previous, r)) → motive x_2