milestone update in ground_2 and basic_2A

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / etc / delift / cpr_delift.etc

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/etc/delift/cpr_delift.etc b/matita/matita/contribs/lambdadelta/basic_2A/etc/delift/cpr_delift.etc
new file mode 100644 (file)
index 0000000..04eb4ae
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2A/etc/delift/cpr_delift.etc
@@ -0,0 +1,37 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/unfold/thin_delift.ma".
+include "basic_2/reducibility/tpr_delift.ma".
+include "basic_2/reducibility/cpr.ma".
+
+(* CONTEXT-SENSITIVE PARALLEL REDUCTION ON TERMS ****************************)
+
+(* Properties on inverse basic term relocation ******************************)
+
+(* Basic_1: was only: pr2_gen_cabbr *)
+lemma thin_cpr_delift_conf: ∀L,U1,U2. L ⊢ U1 ➡ U2 →
+                            ∀K,d,e. ▼*[d, e] L ≡ K → ∀T1. L ⊢ ▼*[d, e] U1 ≡ T1 →
+                            ∃∃T2. K ⊢ T1 ➡ T2 & L ⊢ ▼*[d, e] U2 ≡ T2.
+#L #U1 #U2 * #U #HU1 #HU2 #K #d #e #HLK #T1 #HTU1
+elim (tpr_delift_conf … HU1 … HTU1) -U1 #T #HT1 #HUT
+elim (le_or_ge (|L|) d) #Hd
+[ elim (thin_delift_tpss_conf_le … HU2 … HUT … HLK ?)
+| elim (le_or_ge (|L|) (d+e)) #Hde
+  [ elim (thin_delift_tpss_conf_le_up … HU2 … HUT … HLK ? ? ?)
+  | elim (thin_delift_tpss_conf_be … HU2 … HUT … HLK ? ?)
+  ]
+] -U -HLK // -Hd [2,3: -Hde] #T2 #HT2
+lapply (cpr_intro … HT1 HT2) -T /2 width=3/
+qed.