--- /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/gr_isi_uni.ma".
+include "ground/relocation/gr_isu.ma".
+
+(* UNIFORMITY CONDITION FOR GENERIC RELOCATION MAPS ***********************************************************)
+
+(* Properties with gr_uni **************************************)
+
+(*** isuni_uni *)
+lemma gr_isu_uni (n): 𝐔❪𝐮❨n❩❫.
+#n @(nat_ind_succ … n) -n
+/3 width=3 by gr_isu_isi, gr_isu_next/
+qed.
+
+(*** uni_inv_isuni *)
+lemma gr_isu_eq_repl_back:
+ gr_eq_repl_back … gr_isu.
+#f1 #H elim H -f1
+[ /3 width=3 by gr_isu_isi, gr_isi_eq_repl_back/
+| #f1 #_ #g1 * #IH #f2 #H -g1
+ elim (gr_eq_inv_next_sn … H) -H
+ /3 width=3 by gr_isu_next/
+]
+qed-.
+
+lemma gr_isu_eq_repl_fwd:
+ gr_eq_repl_fwd … gr_isu.
+/3 width=3 by gr_isu_eq_repl_back, gr_eq_repl_sym/ qed-.
+
+(* Inversion lemmas with gr_uni ********************************)
+
+(*** uni_isuni *)
+lemma gr_isu_inv_uni (f): 𝐔❪f❫ → ∃n. 𝐮❨n❩ ≡ f.
+#f #H elim H -f
+[ /3 width=2 by gr_isi_inv_uni, ex_intro/
+| #f #_ #g #H * /3 width=6 by gr_eq_next, ex_intro/
+]
+qed-.