- dependences on ceq and ceq_ext fixed

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / relocation / drops_cext2.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/relocation/drops_cext2.ma b/matita/matita/contribs/lambdadelta/basic_2/relocation/drops_cext2.ma
new file mode 100644 (file)
index 0000000..f2a857d
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2/relocation/drops_cext2.ma
@@ -0,0 +1,29 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/relocation/drops.ma".
+
+(* GENERIC SLICING FOR LOCAL ENVIRONMENTS ***********************************)
+
+(* Properties with the extension to binders of a context-sensitive relation *)
+
+lemma cext2_d_liftable2_sn: ∀R. d_liftable2_sn … lifts R →
+                            d_liftable2_sn … liftsb (cext2 R).
+#R #HR #K #I1 #I2 * -I1 -I2 #I [| #T1 #T2 #HT12 ]
+#b #f #L #HLK #Z1 #H
+[ lapply (liftsb_inv_unit_sn … H)
+| lapply (liftsb_inv_pair_sn … H) * #U1 #HTU1
+] -H #H destruct /3 width=3 by ext2_unit, ex2_intro/
+elim (HR … HT12 … HLK … HTU1) -HR -b -K -T1 /3 width=3 by ext2_pair, ex2_intro/
+qed-.