--- /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/computation/fpbg_fpbs.ma".
+
+(* EXAMPLES *****************************************************************)
+
+(* Reflexivity of proper qrst-computation: the term ApplOmega ***************)
+
+definition ApplDelta: term → nat → term ≝ λW,s. +ⓛW.ⓐ⋆s.ⓐ#0.#0.
+
+definition ApplOmega1: term → nat → term ≝ λW,s. ⓐ(ApplDelta W s).(ApplDelta W s).
+
+definition ApplOmega2: term → nat → term ≝ λW,s. +ⓓⓝW.(ApplDelta W s).ⓐ⋆s.ⓐ#0.#0.
+
+definition ApplOmega3: term → nat → term ≝ λW,s. ⓐ⋆s.(ApplOmega1 W s).
+
+(* Basic properties *********************************************************)
+
+lemma ApplDelta_lift: ∀W1,W2,s,l,k. ⬆[l, k] W1 ≡ W2 →
+ ⬆[l, k] (ApplDelta W1 s) ≡ (ApplDelta W2 s).
+/5 width=1 by lift_flat, lift_bind, lift_lref_lt/ qed.
+
+lemma cpr_ApplOmega_12: ∀G,L,W,s. ⦃G, L⦄ ⊢ ApplOmega1 W s ➡ ApplOmega2 W s.
+/2 width=1 by cpr_beta/ qed.
+
+lemma cpr_ApplOmega_23: ∀G,L,W,s. ⦃G, L⦄ ⊢ ApplOmega2 W s ➡ ApplOmega3 W s.
+#G #L #W1 #s elim (lift_total W1 0 1) #W2 #HW12
+@(cpr_zeta … (ApplOmega3 W2 s)) /4 width=1 by ApplDelta_lift, lift_flat/
+@cpr_flat // @cpr_flat @(cpr_delta … (ApplDelta W1 s) ? 0)
+[3,5,8,10: /2 width=2 by ApplDelta_lift/ |4,9: /2 width=1 by cpr_eps/ |*: skip ]
+qed.
+
+lemma cpxs_ApplOmega_13: ∀h,o,G,L,W,s. ⦃G, L⦄ ⊢ ApplOmega1 W s ➡*[h,o] ApplOmega3 W s.
+/4 width=3 by cpxs_strap1, cpr_cpx/ qed.
+
+lemma fqup_ApplOmega_13: ∀G,L,W,s. ⦃G, L, ApplOmega3 W s⦄ ⊐+ ⦃G, L, ApplOmega1 W s⦄.
+/2 width=1 by/ qed.
+
+(* Main properties **********************************************************)
+
+theorem fpbg_refl: ∀h,o,G,L,W,s. ⦃G, L, ApplOmega1 W s⦄ >≡[h,o] ⦃G, L, ApplOmega1 W s⦄.
+/3 width=5 by fpbs_fpbg_trans, fqup_fpbg, cpxs_fpbs/ qed.