{α : Type u} →
  {β : α → Type v} →
    [inst : Ord α] →
      {motive : Std.DTreeMap.Internal.RioSliceData α β → Sort u_1} →
        (t : Std.DTreeMap.Internal.RioSliceData α β) →
          ((treeMap : Std.DTreeMap.Internal.Impl α β) →
              (range : Std.Rio α) → motive { treeMap := treeMap, range := range }) →
            motive t