milestone update in ground_2 and basic_2A

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / etc / fpr / cfpr_ltpss.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/etc/fpr/cfpr_ltpss.etc b/matita/matita/contribs/lambdadelta/basic_2A/etc/fpr/cfpr_ltpss.etc
new file mode 100644 (file)
index 0000000..66e102e
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2A/etc/fpr/cfpr_ltpss.etc
@@ -0,0 +1,39 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/reducibility/cpr_lift.ma".
+include "basic_2/reducibility/cpr_ltpss_sn.ma".
+include "basic_2/reducibility/cfpr.ma".
+
+(* CONTEXT-SENSITIVE PARALLEL REDUCTION ON CLOSURES *************************)
+
+(* Advanced inversion lemmas ************************************************)
+
+lemma cfpr_inv_pair1: ∀I,L,K1,L2,V1,T1,T2. L ⊢ ⦃⋆.ⓑ{I}V1@@K1, T1⦄ ➡ ⦃L2, T2⦄ →
+                      ∃∃K2,V,V2. V1 ➡ V & L ⊢ V ▶* [0, |L|] V2 &
+                                 L.ⓑ{I}V ⊢ ⦃K1, T1⦄ ➡ ⦃K2, T2⦄  &
+                                 L2 = ⋆.ⓑ{I}V2@@K2.
+* #L #K1 #L2 #V1 #T1 #T2 * >append_length #H
+elim (length_inv_pos_sn_append … H) -H #I2 #K2 #V2 #HK12 #H destruct
+>shift_append_assoc >shift_append_assoc normalize in ⊢ (??%%→?); #H
+[ elim (cpr_inv_abbr1 … H) -H *
+  [ #V #V0 #T0 #HV1 #HV0 #HT10 #H destruct /3 width=7/
+  | #T0 #_ #_ #H destruct
+  ]
+| elim (cpr_inv_abst1 … H Abst V2) -H
+  #V #T * #V0 #HV10 #HV0 #HT1 #H destruct
+  lapply (ltpss_sn_cpr_trans (L.ⓛV0) … 0 (|L|+1) … HT1) -HT1 /2 width=1/ #HT12
+  /3 width=7/
+]
+qed-.