--- /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_2A/computation/fpbs_aaa.ma".
+include "basic_2A/computation/csx_aaa.ma".
+include "basic_2A/computation/fsb_csx.ma".
+
+(* "QRST" STRONGLY NORMALIZING CLOSURES *************************************)
+
+(* Main properties **********************************************************)
+
+(* Note: this is the "big tree" theorem ("RST" version) *)
+theorem aaa_fsb: ∀h,g,G,L,T,A. ⦃G, L⦄ ⊢ T ⁝ A → ⦥[h, g] ⦃G, L, T⦄.
+/3 width=2 by aaa_csx, csx_fsb/ qed.
+
+(* Note: this is the "big tree" theorem ("QRST" version) *)
+theorem aaa_fsba: ∀h,g,G,L,T,A. ⦃G, L⦄ ⊢ T ⁝ A → ⦥⦥[h, g] ⦃G, L, T⦄.
+/3 width=2 by fsb_fsba, aaa_fsb/ qed.
+
+(* Advanced eliminators on atomica arity assignment for terms ***************)
+
+fact aaa_ind_fpb_aux: ∀h,g. ∀R:relation3 genv lenv term.
+ (∀G1,L1,T1,A. ⦃G1, L1⦄ ⊢ T1 ⁝ A →
+ (∀G2,L2,T2. ⦃G1, L1, T1⦄ ≻[h, g] ⦃G2, L2, T2⦄ → R G2 L2 T2) →
+ R G1 L1 T1
+ ) →
+ ∀G,L,T. ⦃G, L⦄ ⊢ ⬊*[h, g] T → ∀A. ⦃G, L⦄ ⊢ T ⁝ A → R G L T.
+#h #g #R #IH #G #L #T #H @(csx_ind_fpb … H) -G -L -T
+#G1 #L1 #T1 #H1 #IH1 #A1 #HTA1 @IH -IH //
+#G2 #L2 #T2 #H12 elim (fpbs_aaa_conf h g … G2 … L2 … T2 … HTA1) -A1
+/2 width=2 by fpb_fpbs/
+qed-.
+
+lemma aaa_ind_fpb: ∀h,g. ∀R:relation3 genv lenv term.
+ (∀G1,L1,T1,A. ⦃G1, L1⦄ ⊢ T1 ⁝ A →
+ (∀G2,L2,T2. ⦃G1, L1, T1⦄ ≻[h, g] ⦃G2, L2, T2⦄ → R G2 L2 T2) →
+ R G1 L1 T1
+ ) →
+ ∀G,L,T,A. ⦃G, L⦄ ⊢ T ⁝ A → R G L T.
+/4 width=4 by aaa_ind_fpb_aux, aaa_csx/ qed-.
+
+fact aaa_ind_fpbg_aux: ∀h,g. ∀R:relation3 genv lenv term.
+ (∀G1,L1,T1,A. ⦃G1, L1⦄ ⊢ T1 ⁝ A →
+ (∀G2,L2,T2. ⦃G1, L1, T1⦄ >≡[h, g] ⦃G2, L2, T2⦄ → R G2 L2 T2) →
+ R G1 L1 T1
+ ) →
+ ∀G,L,T. ⦃G, L⦄ ⊢ ⬊*[h, g] T → ∀A. ⦃G, L⦄ ⊢ T ⁝ A → R G L T.
+#h #g #R #IH #G #L #T #H @(csx_ind_fpbg … H) -G -L -T
+#G1 #L1 #T1 #H1 #IH1 #A1 #HTA1 @IH -IH //
+#G2 #L2 #T2 #H12 elim (fpbs_aaa_conf h g … G2 … L2 … T2 … HTA1) -A1
+/2 width=2 by fpbg_fwd_fpbs/
+qed-.
+
+lemma aaa_ind_fpbg: ∀h,g. ∀R:relation3 genv lenv term.
+ (∀G1,L1,T1,A. ⦃G1, L1⦄ ⊢ T1 ⁝ A →
+ (∀G2,L2,T2. ⦃G1, L1, T1⦄ >≡[h, g] ⦃G2, L2, T2⦄ → R G2 L2 T2) →
+ R G1 L1 T1
+ ) →
+ ∀G,L,T,A. ⦃G, L⦄ ⊢ T ⁝ A → R G L T.
+/4 width=4 by aaa_ind_fpbg_aux, aaa_csx/ qed-.