--- /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/unwind_k/unwind2_rmap_closed.ma".
+
+(* TAILED UNWIND FOR RELOCATION MAP *****************************************)
+
+(* Crucial constructions with tr_uni ****************************************)
+
+(* Note: crux of the commutation between unwind and balanced focused reduction *)
+lemma unwind2_rmap_uni_crux (f) (p) (b) (q) (m) (n):
+ b ϵ 𝐂❨Ⓕ,m,𝟎❩ → q ϵ 𝐂❨Ⓕ,n,𝟎❩ →
+ (𝐮❨↑(♭b+♭q)❩ ∘ ▶[f]p ≗ ▶[f](p●𝗔◗b●𝗟◗q) ∘ 𝐮❨↑(m+n)❩).
+#f #p #b #q #m #n #Hm #Hn
+<list_append_rcons_sn <list_append_rcons_sn >list_append_assoc
+>list_append_rcons_sn >(list_append_rcons_sn … b)
+@(stream_eq_trans … (tr_compose_uni_dx_pap …)) <tr_pap_succ_nap
+@(stream_eq_trans ????? (tr_compose_eq_repl …))
+[| @tls_succ_plus_unwind2_rmap_append_closed_Lq_dx // | skip
+| <nap_plus_unwind2_rmap_append_closed_Lq_dx // | skip
+] -Hn
+@tr_eq_inv_nap_zero_tl_bi
+[ <tr_compose_nap <tr_compose_nap <tr_uni_nap <tr_uni_nap
+ >nsucc_unfold >nplus_succ_dx >nplus_succ_dx <nplus_assoc <nplus_assoc
+ >tr_nap_plus_dx <unwind2_rmap_append <nap_plus_unwind2_rmap_closed
+ /2 width=4 by pcc_A_sn/
+| @(stream_eq_canc_sn … (tr_tl_compose_uni_sn …))
+ @(stream_eq_trans ????? (tr_tl_compose_uni_sn …))
+ >stream_tls_succ <unwind2_rmap_append
+ /3 width=2 by tls_succ_unwind2_rmap_closed, pcc_A_sn/
+]
+qed-.