update in lambdadelta

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / reduction / cnr_lift.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/reduction/cnr_lift.ma b/matita/matita/contribs/lambdadelta/basic_2A/reduction/cnr_lift.ma
new file mode 100644 (file)
index 0000000..4ff641f
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+++ b/matita/matita/contribs/lambdadelta/basic_2A/reduction/cnr_lift.ma
@@ -0,0 +1,49 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/reduction/cpr_lift.ma".
+include "basic_2A/reduction/cnr.ma".
+
+(* NORMAL TERMS FOR CONTEXT-SENSITIVE REDUCTION *****************************)
+
+(* Advanced properties ******************************************************)
+
+(* Basic_1: was: nf2_lref_abst *)
+lemma cnr_lref_abst: ∀G,L,K,V,i. ⬇[i] L ≡ K. ⓛV → ⦃G, L⦄ ⊢ ➡ 𝐍⦃#i⦄.
+#G #L #K #V #i #HLK #X #H
+elim (cpr_inv_lref1 … H) -H // *
+#K0 #V1 #V2 #HLK0 #_ #_
+lapply (drop_mono … HLK … HLK0) -L #H destruct
+qed.
+
+(* Relocation properties ****************************************************)
+
+(* Basic_1: was: nf2_lift *)
+lemma cnr_lift: ∀G,L0,L,T,T0,s,l,m. ⦃G, L⦄ ⊢ ➡ 𝐍⦃T⦄ →
+                ⬇[s, l, m] L0 ≡ L → ⬆[l, m] T ≡ T0 → ⦃G, L0⦄ ⊢ ➡ 𝐍⦃T0⦄.
+#G #L0 #L #T #T0 #s #l #m #HLT #HL0 #HT0 #X #H
+elim (cpr_inv_lift1 … H … HL0 … HT0) -L0 #T1 #HT10 #HT1
+<(HLT … HT1) in HT0; -L #HT0
+>(lift_mono … HT10 … HT0) -T1 -X //
+qed.
+
+(* Note: this was missing in basic_1 *)
+lemma cnr_inv_lift: ∀G,L0,L,T,T0,s,l,m. ⦃G, L0⦄ ⊢ ➡ 𝐍⦃T0⦄ →
+                    ⬇[s, l, m] L0 ≡ L → ⬆[l, m] T ≡ T0 → ⦃G, L⦄ ⊢ ➡ 𝐍⦃T⦄.
+#G #L0 #L #T #T0 #s #l #m #HLT0 #HL0 #HT0 #X #H
+elim (lift_total X l m) #X0 #HX0
+lapply (cpr_lift … H … HL0 … HT0 … HX0) -L #HTX0
+>(HLT0 … HTX0) in HX0; -L0 -X0 #H
+>(lift_inj … H … HT0) -T0 -X -s -l -m //
+qed-.