--- /dev/null
+(**************************************************************************)
+(* ___ *)
+(* ||M|| *)
+(* ||A|| A project by Andrea Asperti *)
+(* ||T|| *)
+(* ||I|| Developers: *)
+(* ||T|| The HELM team. *)
+(* ||A|| http://helm.cs.unibo.it *)
+(* \ / *)
+(* \ / This file is distributed under the terms of the *)
+(* v GNU General Public License Version 2 *)
+(* *)
+(**************************************************************************)
+
+include "delayed_updating/syntax/path_structure.ma".
+include "delayed_updating/syntax/path_labels.ma".
+
+(* STRUCTURE FOR PATH *******************************************************)
+
+(* Constructions with labels ************************************************)
+
+lemma structure_labels_L (n):
+ (𝗟∗∗n) = ⊗(𝗟∗∗n).
+#n @(nat_ind_succ … n) -n //
+qed.