X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fdelayed_updating%2Fsubstitution%2Fprelift_label.ma;h=be57d860180a561ba424518e904d247acca207d1;hb=5c2d38b46908f662cbb717156b29101ff30f8352;hp=e4a9c0596c7ba79d887f94a20ce4c1731003b100;hpb=3af42b8f2cb1956eed14edcc0adb9df92601f248;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/substitution/prelift_label.ma b/matita/matita/contribs/lambdadelta/delayed_updating/substitution/prelift_label.ma
index e4a9c0596..be57d8601 100644
--- a/matita/matita/contribs/lambdadelta/delayed_updating/substitution/prelift_label.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/substitution/prelift_label.ma
@@ -14,13 +14,13 @@
 
 include "delayed_updating/notation/functions/uparrow_2.ma".
 include "delayed_updating/syntax/label.ma".
-include "ground/relocation/tr_pap.ma".
+include "ground/relocation/tr_pap_pap.ma".
 
 (* PRELIFT FOR LABEL ********************************************************)
 
 definition prelift_label (f) (l): label ≝
 match l with
-[ label_d n ⇒ 𝗱(f＠⧣❨n❩)
+[ label_d k ⇒ 𝗱(f＠⧣❨k❩)
 | label_m   ⇒ 𝗺
 | label_L   ⇒ 𝗟
 | label_A   ⇒ 𝗔
@@ -33,8 +33,8 @@ interpretation
 
 (* Basic constructions ******************************************************)
 
-lemma prelift_label_d (f) (n):
-      (𝗱(f＠⧣❨n❩)) = ↑[f]𝗱n.
+lemma prelift_label_d (f) (k):
+      (𝗱(f＠⧣❨k❩)) = ↑[f]𝗱k.
 // qed.
 
 lemma prelift_label_m (f):
@@ -52,3 +52,76 @@ lemma prelift_label_A (f):
 lemma prelift_label_S (f):
       (𝗦) = ↑[f]𝗦.
 // qed.
+
+(* Basic inversions *********************************************************)
+
+lemma prelift_label_inv_d_sn (f) (l) (k1):
+      (𝗱k1) = ↑[f]l →
+      ∃∃k2. k1 = f＠⧣❨k2❩ & 𝗱k2 = l.
+#f * [ #k ] #k1
+[ <prelift_label_d
+| <prelift_label_m
+| <prelift_label_L
+| <prelift_label_A
+| <prelift_label_S
+] #H0 destruct
+/2 width=3 by ex2_intro/
+qed-.
+
+lemma prelift_label_inv_m_sn (f) (l):
+      (𝗺) = ↑[f]l → 𝗺 = l.
+#f * [ #k ]
+[ <prelift_label_d
+| <prelift_label_m
+| <prelift_label_L
+| <prelift_label_A
+| <prelift_label_S
+] #H0 destruct //
+qed-.
+
+lemma prelift_label_inv_L_sn (f) (l):
+      (𝗟) = ↑[f]l → 𝗟 = l.
+#f * [ #k ]
+[ <prelift_label_d
+| <prelift_label_m
+| <prelift_label_L
+| <prelift_label_A
+| <prelift_label_S
+] #H0 destruct //
+qed-.
+
+lemma prelift_label_inv_A_sn (f) (l):
+      (𝗔) = ↑[f]l → 𝗔 = l.
+#f * [ #k ]
+[ <prelift_label_d
+| <prelift_label_m
+| <prelift_label_L
+| <prelift_label_A
+| <prelift_label_S
+] #H0 destruct //
+qed-.
+
+lemma prelift_label_inv_S_sn (f) (l):
+      (𝗦) = ↑[f]l → 𝗦 = l.
+#f * [ #k ]
+[ <prelift_label_d
+| <prelift_label_m
+| <prelift_label_L
+| <prelift_label_A
+| <prelift_label_S
+] #H0 destruct //
+qed-.
+
+(* Main inversions **********************************************************)
+
+theorem prelift_label_inj (f) (l1) (l2):
+        ↑[f]l1 = ↑[f]l2 → l1 = l2.
+#f * [ #k1 ] #l2 #Hl
+[ elim (prelift_label_inv_d_sn … Hl) -Hl #k2 #Hk #H0 destruct
+  >(tr_pap_inj ???? Hk) -Hk //
+| <(prelift_label_inv_m_sn … Hl) -l2 //
+| <(prelift_label_inv_L_sn … Hl) -l2 //
+| <(prelift_label_inv_A_sn … Hl) -l2 //
+| <(prelift_label_inv_S_sn … Hl) -l2 //
+]
+qed-.