--- /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/notation/functions/droppreds_2.ma".
+include "ground/relocation/rtmap_pushs.ma".
+include "ground/relocation/rtmap_tl.ma".
+
+(* RELOCATION MAP ***********************************************************)
+
+rec definition tls (f:rtmap) (n:nat) on n: rtmap ≝ match n with
+[ O ⇒ f | S m ⇒ ⫱(tls f m) ].
+
+interpretation "tls (rtmap)" 'DropPreds n f = (tls f n).
+
+(* Basic properties *********************************************************)
+
+lemma tls_O: ∀f. f = ⫱*[0] f.
+// qed.
+
+lemma tls_S: ∀f,n. ⫱ ⫱*[n] f = ⫱*[↑n] f.
+// qed.
+
+lemma tls_eq_repl: ∀n. eq_repl (λf1,f2. ⫱*[n] f1 ≡ ⫱*[n] f2).
+#n elim n -n /3 width=1 by tl_eq_repl/
+qed.
+
+(* Advanced properties ******************************************************)
+
+lemma tls_xn: ∀n,f. ⫱*[n] ⫱f = ⫱*[↑n] f.
+#n elim n -n //
+qed.
+
+(* Properties with pushs ****************************************************)
+
+lemma tls_pushs: ∀n,f. f = ⫱*[n] ⫯*[n] f.
+#n elim n -n //
+#n #IH #f <tls_xn //
+qed.