X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fdynamic%2Fcnv_aaa.ma;h=c63a1aa1209760964af4074632213d6ba11978b8;hb=87f57ddc367303c33e19c83cd8989cd561f3185b;hp=cad9f2318eb1f978613c2fd894441da4bd011dc3;hpb=bf2b1df641df98a3b614a8c3d53edee8beb0964a;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv_aaa.ma b/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv_aaa.ma
index cad9f2318..c63a1aa12 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv_aaa.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/dynamic/cnv_aaa.ma
@@ -12,7 +12,9 @@
 (*                                                                        *)
 (**************************************************************************)
 
+include "ground_2/lib/arith_2b.ma".
 include "basic_2/rt_computation/cpms_aaa.ma".
+include "basic_2/rt_computation/lprs_cpms.ma".
 include "basic_2/dynamic/cnv.ma".
 
 (* CONTEXT-SENSITIVE NATIVE VALIDITY FOR TERMS ******************************)
@@ -58,3 +60,22 @@ lemma cnv_fwd_cpms_total (a) (h) (n) (G) (L):
 elim (cnv_fwd_aaa … H) -H #A #HA
 /2 width=2 by cpms_total_aaa/
 qed-.
+
+(* Advanced inversion lemmas ************************************************)
+
+lemma cnv_inv_appl_pred (a) (h) (G) (L):
+      ∀V,T. ⦃G, L⦄ ⊢ ⓐV.T ![yinj a, h] →
+      ∃∃p,W0,U0. ⦃G, L⦄ ⊢ V ![a, h] & ⦃G, L⦄ ⊢ T ![a, h] &
+                   ⦃G, L⦄ ⊢ V ➡*[1, h] W0 & ⦃G, L⦄ ⊢ T ➡*[↓a, h] ⓛ{p}W0.U0.
+#a #h #G #L #V #T #H
+elim (cnv_inv_appl … H) -H #n #p #W #U #Ha #HV #HT #HVW #HTU
+lapply (ylt_inv_inj … Ha) -Ha #Ha
+elim (cnv_fwd_aaa … HT) #A #HA
+elim (cpms_total_aaa h … (a-↑n) … (ⓛ{p}W.U))
+[|*: /2 width=8 by cpms_aaa_conf/ ] -HA #X #HU0
+elim (cpms_inv_abst_sn … HU0) #W0 #U0 #HW0 #_ #H destruct
+lapply (cpms_trans … HVW … HW0) -HVW -HW0 #HVW0
+lapply (cpms_trans … HTU … HU0) -HTU -HU0
+>(arith_m2 … Ha) -Ha #HTU0
+/2 width=5 by ex4_3_intro/
+qed-.