update in lambdadelta

[helm.git] / matita / matita / contribs / lambdadelta / basic_2A / static / lsubr_lsubr.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/static/lsubr_lsubr.ma b/matita/matita/contribs/lambdadelta/basic_2A/static/lsubr_lsubr.ma
new file mode 100644 (file)
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+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/static/lsubr.ma".
+
+(* RESTRICTED LOCAL ENVIRONMENT REFINEMENT **********************************)
+
+(* Auxiliary inversion lemmas ***********************************************)
+
+fact lsubr_inv_pair1_aux: ∀L1,L2. L1 ⫃ L2 → ∀I,K1,X. L1 = K1.ⓑ{I}X →
+                          ∨∨ L2 = ⋆
+                           | ∃∃K2. K1 ⫃ K2 & L2 = K2.ⓑ{I}X
+                           | ∃∃K2,V,W. K1 ⫃ K2 & L2 = K2.ⓛW &
+                                       I = Abbr & X = ⓝW.V.
+#L1 #L2 * -L1 -L2
+[ #L #J #K1 #X #H destruct /2 width=1 by or3_intro0/
+| #I #L1 #L2 #V #HL12 #J #K1 #X #H destruct /3 width=3 by or3_intro1, ex2_intro/
+| #L1 #L2 #V #W #HL12 #J #K1 #X #H destruct /3 width=6 by or3_intro2, ex4_3_intro/
+]
+qed-.
+
+lemma lsubr_inv_pair1: ∀I,K1,L2,X. K1.ⓑ{I}X ⫃ L2 →
+                       ∨∨ L2 = ⋆
+                        | ∃∃K2. K1 ⫃ K2 & L2 = K2.ⓑ{I}X
+                        | ∃∃K2,V,W. K1 ⫃ K2 & L2 = K2.ⓛW &
+                                    I = Abbr & X = ⓝW.V.
+/2 width=3 by lsubr_inv_pair1_aux/ qed-.
+
+(* Main properties **********************************************************)
+
+theorem lsubr_trans: Transitive … lsubr.
+#L1 #L #H elim H -L1 -L
+[ #L1 #X #H
+  lapply (lsubr_inv_atom1 … H) -H //
+| #I #L1 #L #V #_ #IHL1 #X #H
+  elim (lsubr_inv_pair1 … H) -H // *
+  #L2 [2: #V2 #W2 ] #HL2 #H1 [ #H2 #H3 ] destruct /3 width=1 by lsubr_pair, lsubr_beta/
+| #L1 #L #V1 #W #_ #IHL1 #X #H
+  elim (lsubr_inv_abst1 … H) -H // *
+  #L2 #HL2 #H destruct /3 width=1 by lsubr_beta/
+]
+qed-.