X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fstatic%2Flfxs_drops.ma;h=76adfa38b376b35601af4a65037f1bf2ca3620bc;hb=5c186c72f508da0849058afeecc6877cd9ed6303;hp=0a3f287bb168a152e26e85cf0a546b2b6b270ee7;hpb=f4787814123d74c9504e988137c2c13279838257;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_drops.ma b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_drops.ma
index 0a3f287bb..76adfa38b 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_drops.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/static/lfxs_drops.ma
@@ -12,45 +12,62 @@
 (*                                                                        *)
 (**************************************************************************)
 
-include "basic_2/relocation/drops_ceq.ma".
+include "basic_2/relocation/drops_cext2.ma".
 include "basic_2/relocation/drops_lexs.ma".
 include "basic_2/static/frees_drops.ma".
 include "basic_2/static/lfxs.ma".
 
 (* GENERIC EXTENSION ON REFERRED ENTRIES OF A CONTEXT-SENSITIVE REALTION ****)
 
-definition dedropable_sn: predicate (relation3 lenv term term) ≝
-                          λR. ∀b,f,L1,K1. ⬇*[b, f] L1 ≡ K1 →
-                          ∀K2,T. K1 ⦻*[R, T] K2 → ∀U. ⬆*[f] T ≡ U →
-                          ∃∃L2. L1 ⦻*[R, U] L2 & ⬇*[b, f] L2 ≡ K2 & L1 ≡[f] L2.
+definition f_dedropable_sn: predicate (relation3 lenv term term) ≝
+                            λR. ∀b,f,L1,K1. ⬇*[b, f] L1 ≘ K1 →
+                            ∀K2,T. K1 ⪤*[R, T] K2 → ∀U. ⬆*[f] T ≘ U →
+                            ∃∃L2. L1 ⪤*[R, U] L2 & ⬇*[b, f] L2 ≘ K2 & L1 ≡[f] L2.
 
-definition dropable_sn: predicate (relation3 lenv term term) ≝
-                        λR. ∀b,f,L1,K1. ⬇*[b, f] L1 ≡ K1 → 𝐔⦃f⦄ →
-                        ∀L2,U. L1 ⦻*[R, U] L2 → ∀T. ⬆*[f] T ≡ U →
-                        ∃∃K2. K1 ⦻*[R, T] K2 & ⬇*[b, f] L2 ≡ K2.
+definition f_dropable_sn: predicate (relation3 lenv term term) ≝
+                          λR. ∀b,f,L1,K1. ⬇*[b, f] L1 ≘ K1 → 𝐔⦃f⦄ →
+                          ∀L2,U. L1 ⪤*[R, U] L2 → ∀T. ⬆*[f] T ≘ U →
+                          ∃∃K2. K1 ⪤*[R, T] K2 & ⬇*[b, f] L2 ≘ K2.
 
-definition dropable_dx: predicate (relation3 lenv term term) ≝
-                        λR. ∀L1,L2,U. L1 ⦻*[R, U] L2 →
-                        ∀b,f,K2. ⬇*[b, f] L2 ≡ K2 → 𝐔⦃f⦄ → ∀T. ⬆*[f] T ≡ U →
-                        ∃∃K1. ⬇*[b, f] L1 ≡ K1 & K1 ⦻*[R, T] K2.
+definition f_dropable_dx: predicate (relation3 lenv term term) ≝
+                          λR. ∀L1,L2,U. L1 ⪤*[R, U] L2 →
+                          ∀b,f,K2. ⬇*[b, f] L2 ≘ K2 → 𝐔⦃f⦄ → ∀T. ⬆*[f] T ≘ U →
+                          ∃∃K1. ⬇*[b, f] L1 ≘ K1 & K1 ⪤*[R, T] K2.
+
+definition f_transitive_next: relation3 … ≝ λR1,R2,R3.
+                              ∀f,L,T. L ⊢ 𝐅*⦃T⦄ ≘ f →
+                              ∀g,I,K,n. ⬇*[n] L ≘ K.ⓘ{I} → ↑g = ⫱*[n] f →
+                              lexs_transitive (cext2 R1) (cext2 R2) (cext2 R3) (cext2 R1) cfull g K I.
 
 (* Properties with generic slicing for local environments *******************)
 
-(* Basic_2A1: includes: llpx_sn_lift_le llpx_sn_lift_ge *)
-lemma lfxs_liftable_dedropable: ∀R. (∀L. reflexive ? (R L)) →
-                                d_liftable2 R → dedropable_sn R.
+lemma lfxs_liftable_dedropable_sn: ∀R. (∀L. reflexive ? (R L)) →
+                                   d_liftable2_sn … lifts R → f_dedropable_sn R.
 #R #H1R #H2R #b #f #L1 #K1 #HLK1 #K2 #T * #f1 #Hf1 #HK12 #U #HTU
 elim (frees_total L1 U) #f2 #Hf2
 lapply (frees_fwd_coafter … Hf2 … HLK1 … HTU … Hf1) -HTU #Hf
-elim (lexs_liftable_co_dedropable … H1R … H2R … HLK1 … HK12 … Hf) -f1 -K1
-/3 width=6 by cfull_lift, ex3_intro, ex2_intro/
+elim (lexs_liftable_co_dedropable_sn … HLK1 … HK12 … Hf) -f1 -K1
+/3 width=6 by cext2_d_liftable2_sn, cfull_lift_sn, ext2_refl, ex3_intro, ex2_intro/
 qed-.
 
+lemma lfxs_trans_next: ∀R1,R2,R3. lfxs_transitive R1 R2 R3 → f_transitive_next R1 R2 R3.
+#R1 #R2 #R3 #HR #f #L1 #T #Hf #g #I1 #K1 #n #HLK #Hgf #I #H
+generalize in match HLK; -HLK elim H -I1 -I
+[ #I #_ #L2 #_ #I2 #H
+  lapply (ext2_inv_unit_sn … H) -H #H destruct
+  /2 width=1 by ext2_unit/
+| #I #V1 #V #HV1 #HLK1 #L2 #HL12 #I2 #H
+  elim (ext2_inv_pair_sn … H) -H #V2 #HV2 #H destruct
+  elim (frees_inv_drops_next … Hf … HLK1 … Hgf) -f -HLK1 #f #Hf #Hfg
+  /5 width=5 by ext2_pair, sle_lexs_trans, ex2_intro/
+]
+qed.
+
 (* Inversion lemmas with generic slicing for local environments *************)
 
-(* Basic_2A1: restricts: llpx_sn_inv_lift_le llpx_sn_inv_lift_be llpx_sn_inv_lift_ge *)
+(* Basic_2A1: uses: llpx_sn_inv_lift_le llpx_sn_inv_lift_be llpx_sn_inv_lift_ge *)
 (* Basic_2A1: was: llpx_sn_drop_conf_O *)
-lemma lfxs_dropable_sn: ∀R. dropable_sn R.
+lemma lfxs_dropable_sn: ∀R. f_dropable_sn R.
 #R #b #f #L1 #K1 #HLK1 #H1f #L2 #U * #f2 #Hf2 #HL12 #T #HTU
 elim (frees_total K1 T) #f1 #Hf1
 lapply (frees_fwd_coafter … Hf2 … HLK1 … HTU … Hf1) -HTU #H2f
@@ -60,7 +77,7 @@ qed-.
 
 (* Basic_2A1: was: llpx_sn_drop_trans_O *)
 (* Note: the proof might be simplified *)
-lemma lfxs_dropable_dx: ∀R. dropable_dx R.
+lemma lfxs_dropable_dx: ∀R. f_dropable_dx R.
 #R #L1 #L2 #U * #f2 #Hf2 #HL12 #b #f #K2 #HLK2 #H1f #T #HTU
 elim (drops_isuni_ex … H1f L1) #K1 #HLK1
 elim (frees_total K1 T) #f1 #Hf1
@@ -69,25 +86,39 @@ elim (lexs_co_dropable_dx … HL12 … HLK2 … H2f) -L2
 /4 width=9 by frees_inv_lifts, ex2_intro/
 qed-.
 
-(* Basic_2A1: was: llpx_sn_inv_lift_O *)
-lemma lfxs_inv_lift_bi: ∀R,L1,L2,U. L1 ⦻*[R, U] L2 →
-                        ∀K1,K2,i. ⬇*[i] L1 ≡ K1 → ⬇*[i] L2 ≡ K2 →
-                        ∀T. ⬆*[i] T ≡ U → K1 ⦻*[R, T] K2.
-#R #L1 #L2 #U #HL12 #K1 #K2 #i #HLK1 #HLK2 #T #HTU
+(* Basic_2A1: uses: llpx_sn_inv_lift_O *)
+lemma lfxs_inv_lifts_bi: ∀R,L1,L2,U. L1 ⪤*[R, U] L2 → ∀b,f. 𝐔⦃f⦄ → 
+                         ∀K1,K2. ⬇*[b, f] L1 ≘ K1 → ⬇*[b, f] L2 ≘ K2 →
+                         ∀T. ⬆*[f] T ≘ U → K1 ⪤*[R, T] K2.
+#R #L1 #L2 #U #HL12 #b #f #Hf #K1 #K2 #HLK1 #HLK2 #T #HTU
 elim (lfxs_dropable_sn … HLK1 … HL12 … HTU) -L1 -U // #Y #HK12 #HY
-lapply (drops_mono … HY … HLK2) -L2 -i #H destruct //
+lapply (drops_mono … HY … HLK2) -b -f -L2 #H destruct //
 qed-.
 
-lemma lfxs_inv_lref_sn: ∀R,L1,L2,i. L1 ⦻*[R, #i] L2 → ∀I,K1,V1. ⬇*[i] L1 ≡ K1.ⓑ{I}V1 →
-                        ∃∃K2,V2. ⬇*[i] L2 ≡ K2.ⓑ{I}V2 & K1 ⦻*[R, V1] K2 & R K1 V1 V2.
+lemma lfxs_inv_lref_pair_sn: ∀R,L1,L2,i. L1 ⪤*[R, #i] L2 → ∀I,K1,V1. ⬇*[i] L1 ≘ K1.ⓑ{I}V1 →
+                             ∃∃K2,V2. ⬇*[i] L2 ≘ K2.ⓑ{I}V2 & K1 ⪤*[R, V1] K2 & R K1 V1 V2.
 #R #L1 #L2 #i #HL12 #I #K1 #V1 #HLK1 elim (lfxs_dropable_sn … HLK1 … HL12 (#0)) -HLK1 -HL12 //
 #Y #HY #HLK2 elim (lfxs_inv_zero_pair_sn … HY) -HY
 #K2 #V2 #HK12 #HV12 #H destruct /2 width=5 by ex3_2_intro/
 qed-.
 
-lemma lfxs_inv_lref_dx: ∀R,L1,L2,i. L1 ⦻*[R, #i] L2 → ∀I,K2,V2. ⬇*[i] L2 ≡ K2.ⓑ{I}V2 →
-                        ∃∃K1,V1. ⬇*[i] L1 ≡ K1.ⓑ{I}V1 & K1 ⦻*[R, V1] K2 & R K1 V1 V2.
+lemma lfxs_inv_lref_pair_dx: ∀R,L1,L2,i. L1 ⪤*[R, #i] L2 → ∀I,K2,V2. ⬇*[i] L2 ≘ K2.ⓑ{I}V2 →
+                             ∃∃K1,V1. ⬇*[i] L1 ≘ K1.ⓑ{I}V1 & K1 ⪤*[R, V1] K2 & R K1 V1 V2.
 #R #L1 #L2 #i #HL12 #I #K2 #V2 #HLK2 elim (lfxs_dropable_dx … HL12 … HLK2 … (#0)) -HLK2 -HL12 //
 #Y #HLK1 #HY elim (lfxs_inv_zero_pair_dx … HY) -HY
 #K1 #V1 #HK12 #HV12 #H destruct /2 width=5 by ex3_2_intro/
 qed-.
+
+lemma lfxs_inv_lref_unit_sn: ∀R,L1,L2,i. L1 ⪤*[R, #i] L2 → ∀I,K1. ⬇*[i] L1 ≘ K1.ⓤ{I} →
+                             ∃∃f,K2. ⬇*[i] L2 ≘ K2.ⓤ{I} & K1 ⪤*[cext2 R, cfull, f] K2 & 𝐈⦃f⦄.
+#R #L1 #L2 #i #HL12 #I #K1 #HLK1 elim (lfxs_dropable_sn … HLK1 … HL12 (#0)) -HLK1 -HL12 //
+#Y #HY #HLK2 elim (lfxs_inv_zero_unit_sn … HY) -HY
+#f #K2 #Hf #HK12 #H destruct /2 width=5 by ex3_2_intro/
+qed-.
+
+lemma lfxs_inv_lref_unit_dx: ∀R,L1,L2,i. L1 ⪤*[R, #i] L2 → ∀I,K2. ⬇*[i] L2 ≘ K2.ⓤ{I} →
+                             ∃∃f,K1. ⬇*[i] L1 ≘ K1.ⓤ{I} & K1 ⪤*[cext2 R, cfull, f] K2 & 𝐈⦃f⦄.
+#R #L1 #L2 #i #HL12 #I #K2 #HLK2 elim (lfxs_dropable_dx … HL12 … HLK2 … (#0)) -HLK2 -HL12 //
+#Y #HLK1 #HY elim (lfxs_inv_zero_unit_dx … HY) -HY
+#f #K2 #Hf #HK12 #H destruct /2 width=5 by ex3_2_intro/
+qed-.