--- /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 "ground/relocation/tr_pap_hdtl.ma".
+include "ground/lib/stream_hdtl_eq.ma".
+
+(* POSITIVE APPLICATION FOR TOTAL RELOCATION MAPS ***************************)
+
+(* Inversions with stream_eq and stream_tl **********************************)
+
+lemma tr_eq_inv_pap_unit_tl_bi (f1) (f2):
+ f1@⧣❨𝟏❩ = f2@⧣❨𝟏❩ → ⇂f1 ≗ ⇂f2 → f1 ≗ f2.
+#f1 #f2 #H1 #H2
+/2 width=1 by stream_eq_inv_hd_tl_bi/
+qed-.