X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fi_dynamic%2Fntas_nta.ma;h=17259cb17e45bb9403c73526ecde7f95be0ba517;hb=ba7b8553850e4a33cf8607b07758392230d9ed40;hp=7374d2df420897f58a96962a2874aa50d864b45c;hpb=c0d38a82464481e3c8fd68e4b00d7b9b448df462;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/i_dynamic/ntas_nta.ma b/matita/matita/contribs/lambdadelta/basic_2/i_dynamic/ntas_nta.ma
index 7374d2df4..17259cb17 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/i_dynamic/ntas_nta.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/i_dynamic/ntas_nta.ma
@@ -12,11 +12,68 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "basic_2/dynamic/nta.ma".
-include "basic_2/i_dynamic/ntas.ma".
+include "basic_2/dynamic/nta_preserve.ma".
+include "basic_2/i_dynamic/ntas_preserve.ma".
 
 (* ITERATED NATIVE TYPE ASSIGNMENT FOR TERMS ********************************)
 
+(* Properties with native type assignment for terms *************************)
+
+lemma nta_ntas (h) (a) (G) (L):
+      ∀T,U. ⦃G,L⦄ ⊢ T :[h,a] U → ⦃G,L⦄ ⊢ T :*[h,a,1] U.
+#h #a #G #L #T #U #H
+elim (cnv_inv_cast … H) -H /2 width=3 by ntas_intro/
+qed-.
+
+(* Inversion lemmas with native type assignment for terms *******************)
+
+lemma ntas_inv_nta (h) (a) (G) (L):
+      ∀T,U. ⦃G,L⦄ ⊢ T :*[h,a,1] U → ⦃G,L⦄ ⊢ T :[h,a] U.
+#h #a #G #L #T #U
+* /2 width=3 by cnv_cast/
+qed-.
+
+(* Note: this follows from ntas_inv_appl_sn *)
+lemma nta_inv_appl_sn_ntas (h) (a) (G) (L) (V) (T):
+      ∀X. ⦃G,L⦄ ⊢ ⓐV.T :[h,a] X →
+      ∨∨ ∃∃p,W,U,U0. ad a 0 & ⦃G,L⦄ ⊢ V :[h,a] W & ⦃G,L⦄ ⊢ T :*[h,a,0] ⓛ{p}W.U0 & ⦃G,L.ⓛW⦄ ⊢ U0 :[h,a] U & ⦃G,L⦄ ⊢ ⓐV.ⓛ{p}W.U ⬌*[h] X & ⦃G,L⦄ ⊢ X ![h,a]
+       | ∃∃n,p,W,U,U0. ad a (↑n) & ⦃G,L⦄ ⊢ V :[h,a] W & ⦃G,L⦄ ⊢ T :[h,a] U & ⦃G,L⦄ ⊢ U :*[h,a,n] ⓛ{p}W.U0 & ⦃G,L⦄ ⊢ ⓐV.U ⬌*[h] X & ⦃G,L⦄ ⊢ X ![h,a].
+#h #a #G #L #V #T #X #H
+(*
+lapply (nta_ntas … H) -H #H
+elim (ntas_inv_appl_sn … H) -H * #n #p #W #U #U0 #Hn #Ha #HVW #HTU #HU #HUX #HX
+[ elim (eq_or_gt n) #H destruct
+  [ <minus_n_O in HU; #HU -Hn
+    /4 width=8 by ntas_inv_nta, ex6_4_intro, or_introl/
+  | lapply (le_to_le_to_eq … Hn H) -Hn -H #H destruct
+    <minus_n_n in HU; #HU
+    @or_intror
+    @(ex6_5_intro … Ha … HUX HX) -Ha -X
+    [2,4: /2 width=2 by ntas_inv_nta/
+    |6: @ntas_refl
+*)
+elim (cnv_inv_cast … H) -H #X0 #HX #HVT #HX0 #HTX0
+elim (cnv_inv_appl … HVT) #n #p #W #U0 #Ha #HV #HT #HVW #HTU0
+elim (eq_or_gt n) #Hn destruct
+[ elim (cnv_fwd_cpms_abst_dx_le … HT … HTU0 1) [| // ] <minus_n_O #U #H #HU0
+  lapply (cpms_appl_dx … V V … H) [ // ] -H #H
+  elim (cnv_cpms_conf … HVT … HTX0 … H) -HVT -HTX0 -H <minus_n_n #X1 #HX01 #HUX1
+  lapply (cpms_trans … HX0 … HX01) -X0 #HX1
+  lapply (cprs_div … HUX1 … HX1) -X1 #HUX
+  lapply (cnv_cpms_trans … HT … HTU0) #H
+  elim (cnv_inv_bind … H) -H #_ #HU0
+  /4 width=8 by cnv_cpms_ntas, cnv_cpms_nta, ex6_4_intro, or_introl/
+| >(plus_minus_m_m_commutative … Hn) in HTU0; #H
+  elim (cpms_inv_plus … H) -H #U #HTU #HU0
+  lapply (cpms_appl_dx … V V … HTU) [ // ] #H
+  elim (cnv_cpms_conf … HVT … HTX0 … H) -HVT -HTX0 -H <minus_n_n #X1 #HX01 #HUX1
+  lapply (cpms_trans … HX0 … HX01) -X0 #HX1
+  lapply (cprs_div … HUX1 … HX1) -X1 #HUX
+  <(S_pred … Hn) in Ha; -Hn #Ha
+  /5 width=10 by cnv_cpms_ntas, cnv_cpms_nta, cnv_cpms_trans, ex6_5_intro, or_intror/
+]
+qed-.
+
 (*
 
 definition ntas: sh → lenv → relation term ≝