update in lambdadelta

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

diff --git a/matita/matita/contribs/lambdadelta/basic_2A/static/da_da.ma b/matita/matita/contribs/lambdadelta/basic_2A/static/da_da.ma
new file mode 100644 (file)
index 0000000..ecef4ca
--- /dev/null
+++ b/matita/matita/contribs/lambdadelta/basic_2A/static/da_da.ma
@@ -0,0 +1,38 @@
+(**************************************************************************)
+(*       ___                                                              *)
+(*      ||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/da_lift.ma".
+
+(* DEGREE ASSIGNMENT FOR TERMS **********************************************)
+
+(* Main properties **********************************************************)
+
+theorem da_mono: ∀h,g,G,L,T,d1. ⦃G, L⦄ ⊢ T ▪[h, g] d1 →
+                 ∀d2. ⦃G, L⦄ ⊢ T ▪[h, g] d2 → d1 = d2.
+#h #g #G #L #T #d1 #H elim H -G -L -T -d1
+[ #G #L #k #d1 #Hkd1 #d2 #H
+  lapply (da_inv_sort … H) -G -L #Hkd2
+  >(deg_mono … Hkd2 … Hkd1) -h -k -d2 //
+| #G #L #K #V #i #d1 #HLK #_ #IHV #d2 #H
+  elim (da_inv_lref … H) -H * #K0 #V0 [| #d0 ] #HLK0 #HV0 [| #Hd0 ]
+  lapply (drop_mono … HLK0 … HLK) -HLK -HLK0 #H destruct /2 width=1 by/
+| #G #L #K #W #i #d1 #HLK #_ #IHW #d2 #H
+  elim (da_inv_lref … H) -H * #K0 #W0 [| #d0 ] #HLK0 #HW0 [| #Hd0 ]
+  lapply (drop_mono … HLK0 … HLK) -HLK -HLK0 #H destruct /3 width=1 by eq_f/
+| #a #I #G #L #V #T #d1 #_ #IHT #d2 #H
+  lapply (da_inv_bind … H) -H /2 width=1 by/
+| #I #G #L #V #T #d1 #_ #IHT #d2 #H
+  lapply (da_inv_flat … H) -H /2 width=1 by/
+]
+qed-.