--- /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 "static_2/static/feqg_length.ma".
+
+(* GENERIC EQUIVALENCE FOR CLOSURES ON REFERRED ENTRIES *********************)
+
+(* Properties with structural successor for closures ************************)
+
+lemma fqu_fneqg (S) (b) (G1) (G2) (L1) (L2) (T1) (T2):
+ ❪G1,L1,T1❫ ⬂[b] ❪G2,L2,T2❫ → ❪G1,L1,T1❫ ≛[S] ❪G2,L2,T2❫ → ⊥.
+#S #b #G1 #G2 #L1 #L2 #T1 #T2 #H elim H -G1 -G2 -L1 -L2 -T1 -T2
+[ /3 width=8 by feqg_fwd_length, succ_inv_refl_sn/
+| /3 width=9 by teqg_inv_pair_xy_x, feqg_fwd_teqg/
+| /3 width=9 by teqg_inv_pair_xy_y, feqg_fwd_teqg/
+| /3 width=9 by teqg_inv_pair_xy_y, feqg_fwd_teqg/
+| /3 width=9 by teqg_inv_pair_xy_y, feqg_fwd_teqg/
+| /3 width=8 by feqg_fwd_length, succ_inv_refl_sn/
+]
+qed-.