--- /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 "basic_2/static/lfxs_length.ma".
+include "basic_2/static/lfxs_fsle.ma".
+include "basic_2/static/lfeq.ma".
+
+(* SYNTACTIC EQUIVALENCE FOR LOCAL ENVIRONMENTS ON REFERRED ENTRIES *********)
+
+(* Properties with free variables inclusion for restricted closures *********)
+
+lemma lfeq_fsle_comp: lfxs_fsle_compatible ceq.
+#L1 #L2 #T #HL12
+elim (frees_total L1 T)
+/4 width=8 by frees_lfeq_conf, lfxs_fwd_length, lveq_length_eq, sle_refl, ex4_4_intro/
+qed.
+
+(* Forward lemmas with free variables inclusion for restricted closures *****)
+
+lemma lfeq_lfxs_trans: ∀R. lfeq_transitive R →
+ ∀L1,L,T. L1 ≡[T] L → ∀L2. L ⪤*[R, T] L2 → L1 ⪤*[R, T] L2.
+/4 width=16 by lfeq_fsle_comp, lfxs_trans_fsle, lfxs_trans_next/ qed-.