--- /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/rt_computation/cpxs_tdeq.ma".
+include "basic_2/rt_computation/fpbs_cpxs.ma".
+include "basic_2/rt_computation/fpbg.ma".
+
+(* PROPER PARALLEL RST-COMPUTATION FOR CLOSURES **************************)
+
+(* Properties with uncounted context-sensitive parallel rt-computation ******)
+
+(* Basic_2A1: was: cpxs_fpbg *)
+lemma cpxs_tdneq_fpbg: ∀h,o,G,L,T1,T2. ⦃G, L⦄ ⊢ T1 ⬈*[h] T2 →
+ (T1 ≛[h, o] T2 → ⊥) → ⦃G, L, T1⦄ >[h, o] ⦃G, L, T2⦄.
+#h #o #G #L #T1 #T2 #H #H0
+elim (cpxs_tdneq_fwd_step_sn … H … H0) -H -H0
+/4 width=5 by cpxs_tdeq_fpbs, fpb_cpx, ex2_3_intro/
+qed.