X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fdelayed_updating%2Fsubstitution%2Flift_structure.ma;h=5cc0f1f48dd2769fdda4bf6a55442f76ab1bef89;hb=cfd201c62dd9b854bfb4ada648d3e556b29fac3a;hp=961a5c435ef8b0f3d2cbd106a5bc80279ccf85db;hpb=55ea9387fd71564c629fe3f47fd9bac59c4befb9;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/delayed_updating/substitution/lift_structure.ma b/matita/matita/contribs/lambdadelta/delayed_updating/substitution/lift_structure.ma
index 961a5c435..5cc0f1f48 100644
--- a/matita/matita/contribs/lambdadelta/delayed_updating/substitution/lift_structure.ma
+++ b/matita/matita/contribs/lambdadelta/delayed_updating/substitution/lift_structure.ma
@@ -15,6 +15,8 @@
 include "delayed_updating/substitution/lift_eq.ma".
 include "delayed_updating/syntax/path_structure.ma".
 include "delayed_updating/syntax/path_proper.ma".
+include "ground/xoa/ex_4_2.ma".
+include "ground/xoa/ex_3_2.ma".
 
 (* LIFT FOR PATH ***********************************************************)
 
@@ -31,7 +33,13 @@ lemma lift_structure (p) (f):
 #p @(path_ind_lift … p) -p //
 qed.
 
-(* Properties with proper condition for path ********************************)
+(* Destructions with structure **********************************************)
+
+lemma lift_des_structure (q) (p) (f):
+      ⊗q = ↑[f]p → ⊗q = ⊗p.
+// qed-.
+
+(* Constructions with proper condition for path *****************************)
 
 lemma lift_append_proper_dx (p2) (p1) (f): Ꝕp2 →
       (⊗p1)●(↑[↑[p1]f]p2) = ↑[f](p1●p2).
@@ -49,20 +57,118 @@ qed-.
 
 lemma lift_d_empty_dx (n) (p) (f):
       (⊗p)◖𝗱((↑[p]f)@❨n❩) = ↑[f](p◖𝗱n).
-/3 width=3 by ppc_lcons, lift_append_proper_dx/
+#n #p #f <lift_append_proper_dx // 
 qed.
 
 lemma lift_L_dx (p) (f):
       (⊗p)◖𝗟 = ↑[f](p◖𝗟).
-/3 width=3 by ppc_lcons, lift_append_proper_dx/
+#p #f <lift_append_proper_dx //
 qed.
 
 lemma lift_A_dx (p) (f):
       (⊗p)◖𝗔 = ↑[f](p◖𝗔).
-/3 width=3 by ppc_lcons, lift_append_proper_dx/
+#p #f <lift_append_proper_dx //
 qed.
 
 lemma lift_S_dx (p) (f):
       (⊗p)◖𝗦 = ↑[f](p◖𝗦).
-/3 width=3 by ppc_lcons, lift_append_proper_dx/
+#p #f <lift_append_proper_dx //
 qed.
+
+(* Advanced inversions with proj_path ***************************************)
+
+lemma lift_path_inv_d_sn (k) (q) (p) (f):
+      (𝗱k◗q) = ↑[f]p →
+      ∃∃r,h. 𝐞 = ⊗r & (↑[r]f)@❨h❩ = k & 𝐞  = q & r◖𝗱h = p.
+#k #q #p @(path_ind_lift … p) -p
+[| #n | #n #l #p |*: #p ] [|*: #IH ] #f
+[ <lift_path_empty #H destruct
+| <lift_path_d_empty_sn #H destruct -IH
+  /2 width=5 by ex4_2_intro/
+| <lift_path_d_lcons_sn #H
+  elim (IH … H) -IH -H #r #h #Hr #Hh #Hq #Hp destruct
+  /2 width=5 by ex4_2_intro/
+| <lift_path_L_sn #H destruct
+| <lift_path_A_sn #H destruct
+| <lift_path_S_sn #H destruct
+]
+qed-.
+
+lemma lift_path_inv_L_sn (q) (p) (f):
+      (𝗟◗q) = ↑[f]p →
+      ∃∃r1,r2. 𝐞 = ⊗r1 & q = ↑[⫯↑[r1]f]r2 & r1●𝗟◗r2 = p.
+#q #p @(path_ind_lift … p) -p
+[| #n | #n #l #p |*: #p ] [|*: #IH ] #f
+[ <lift_path_empty #H destruct
+| <lift_path_d_empty_sn #H destruct
+| <lift_path_d_lcons_sn #H
+  elim (IH … H) -IH -H #r1 #r2 #Hr1 #Hq #Hp destruct
+  /2 width=5 by ex3_2_intro/
+| <lift_path_L_sn #H destruct -IH
+  /2 width=5 by ex3_2_intro/
+| <lift_path_A_sn #H destruct
+| <lift_path_S_sn #H destruct
+]
+qed-.
+
+lemma lift_path_inv_A_sn (q) (p) (f):
+      (𝗔◗q) = ↑[f]p →
+      ∃∃r1,r2. 𝐞 = ⊗r1 & q = ↑[↑[r1]f]r2 & r1●𝗔◗r2 = p.
+#q #p @(path_ind_lift … p) -p
+[| #n | #n #l #p |*: #p ] [|*: #IH ] #f
+[ <lift_path_empty #H destruct
+| <lift_path_d_empty_sn #H destruct
+| <lift_path_d_lcons_sn #H
+  elim (IH … H) -IH -H #r1 #r2 #Hr1 #Hq #Hp destruct
+  /2 width=5 by ex3_2_intro/
+| <lift_path_L_sn #H destruct
+| <lift_path_A_sn #H destruct -IH
+  /2 width=5 by ex3_2_intro/
+| <lift_path_S_sn #H destruct
+]
+qed-.
+
+lemma lift_path_inv_S_sn (q) (p) (f):
+      (𝗦◗q) = ↑[f]p →
+      ∃∃r1,r2. 𝐞 = ⊗r1 & q = ↑[↑[r1]f]r2 & r1●𝗦◗r2 = p.
+#q #p @(path_ind_lift … p) -p
+[| #n | #n #l #p |*: #p ] [|*: #IH ] #f
+[ <lift_path_empty #H destruct
+| <lift_path_d_empty_sn #H destruct
+| <lift_path_d_lcons_sn #H
+  elim (IH … H) -IH -H #r1 #r2 #Hr1 #Hq #Hp destruct
+  /2 width=5 by ex3_2_intro/
+| <lift_path_L_sn #H destruct
+| <lift_path_A_sn #H destruct
+| <lift_path_S_sn #H destruct -IH
+  /2 width=5 by ex3_2_intro/
+]
+qed-.
+
+(* Inversions with proper condition for path ********************************)
+
+lemma lift_inv_append_proper_dx (q2) (q1) (p) (f): Ꝕq2 →
+      q1●q2 = ↑[f]p →
+      ∃∃p1,p2. ⊗p1 = q1 & ↑[↑[p1]f]p2 = q2 & p1●p2 = p.
+#q2 #q1 elim q1 -q1
+[ #p #f #Hq2 <list_append_empty_sn #H destruct
+  /2 width=5 by ex3_2_intro/
+| * [ #n1 ] #q1 #IH #p #f #Hq2 <list_append_lcons_sn #H
+  [ elim (lift_path_inv_d_sn … H) -H #r1 #m1 #_ #_ #H0 #_ -IH
+    elim (eq_inv_list_empty_append … H0) -H0 #_ #H0 destruct
+    elim Hq2 -Hq2 //
+  | elim (lift_path_inv_L_sn … H) -H #r1 #s1 #Hr1 #Hs1 #H0 destruct
+    elim (IH … Hs1) -IH -Hs1 // -Hq2 #p1 #p2 #H1 #H2 #H3 destruct
+    @(ex3_2_intro … (r1●𝗟◗p1)) //
+    <structure_append <Hr1 -Hr1 //
+  | elim (lift_path_inv_A_sn … H) -H #r1 #s1 #Hr1 #Hs1 #H0 destruct
+    elim (IH … Hs1) -IH -Hs1 // -Hq2 #p1 #p2 #H1 #H2 #H3 destruct
+    @(ex3_2_intro … (r1●𝗔◗p1)) //
+    <structure_append <Hr1 -Hr1 //
+  | elim (lift_path_inv_S_sn … H) -H #r1 #s1 #Hr1 #Hs1 #H0 destruct
+    elim (IH … Hs1) -IH -Hs1 // -Hq2 #p1 #p2 #H1 #H2 #H3 destruct
+    @(ex3_2_intro … (r1●𝗦◗p1)) //
+    <structure_append <Hr1 -Hr1 //
+  ]
+]
+qed-.