X-Git-Url: http://matita.cs.unibo.it/gitweb/?a=blobdiff_plain;f=matita%2Fmatita%2Fcontribs%2Flambdadelta%2Fbasic_2%2Fsubstitution%2Flleq.ma;h=dc138a492c89e1a3c6b4a9efabc3f4ad100a16c0;hb=7a25b8fcba2436a75556db1725c6e1be78a9faca;hp=577343c6ecbac90fa244c071791078808f1d50ff;hpb=dca4170c5ce5f2cd6be8ae1dc0422bd6a680b43f;p=helm.git

diff --git a/matita/matita/contribs/lambdadelta/basic_2/substitution/lleq.ma b/matita/matita/contribs/lambdadelta/basic_2/substitution/lleq.ma
index 577343c6e..dc138a492 100644
--- a/matita/matita/contribs/lambdadelta/basic_2/substitution/lleq.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/substitution/lleq.ma
@@ -13,153 +13,148 @@
 (**************************************************************************)
 
 include "basic_2/notation/relations/lazyeq_4.ma".
-include "basic_2/substitution/cpys.ma".
+include "basic_2/substitution/llpx_sn.ma".
 
 (* LAZY EQUIVALENCE FOR LOCAL ENVIRONMENTS **********************************)
 
-definition lleq: relation4 ynat term lenv lenv ≝
-                 λd,T,L1,L2. |L1| = |L2| ∧
-                             (∀U. ⦃⋆, L1⦄ ⊢ T ▶*×[d, ∞] U ↔ ⦃⋆, L2⦄ ⊢ T ▶*×[d, ∞] U).
+definition ceq: relation4 bind2 lenv term term ≝ λI,L,T1,T2. T1 = T2.
+
+definition lleq: relation4 ynat term lenv lenv ≝ llpx_sn ceq.
 
 interpretation
    "lazy equivalence (local environment)"
    'LazyEq T d L1 L2 = (lleq d T L1 L2).
 
-(* Basic properties *********************************************************)
-
-lemma lleq_refl: ∀d,T. reflexive … (lleq d T).
-/3 width=1 by conj/ qed.
-
-lemma lleq_sym: ∀d,T. symmetric … (lleq d T).
-#d #T #L1 #L2 * /3 width=1 by iff_sym, conj/
-qed-.
-
-lemma lleq_sort: ∀L1,L2,d,k. |L1| = |L2| → L1 ⋕[⋆k, d] L2.
-#L1 #L2 #d #k #HL12 @conj // -HL12
-#U @conj #H >(cpys_inv_sort1 … H) -H //
-qed.
+definition lleq_transitive: predicate (relation4 bind2 lenv term term) ≝
+           λR. ∀I,L2,T1,T2. R I L2 T1 T2 → ∀L1. L1 ≡[T1, 0] L2 → R I L1 T1 T2.
 
-lemma lleq_gref: ∀L1,L2,d,p. |L1| = |L2| → L1 ⋕[§p, d] L2.
-#L1 #L2 #d #k #HL12 @conj // -HL12
-#U @conj #H >(cpys_inv_gref1 … H) -H //
-qed.
-
-lemma lleq_bind: ∀a,I,L1,L2,V,T,d.
-                 L1 ⋕[V, d] L2 → L1.ⓑ{I}V ⋕[T, ⫯d] L2.ⓑ{I}V →
-                 L1 ⋕[ⓑ{a,I}V.T, d] L2.
-#a #I #L1 #L2 #V #T #d * #HL12 #IHV * #_ #IHT @conj // -HL12
-#X @conj #H elim (cpys_inv_bind1 … H) -H
-#W #U #HVW #HTU #H destruct
-elim (IHV W) -IHV #H1VW #H1WV
-elim (IHT U) -IHT #H1TU #H1UT
-@cpys_bind /2 width=1 by/ -HVW -H1VW -H1WV
-[ @(lsuby_cpys_trans … (L2.ⓑ{I}V))
-| @(lsuby_cpys_trans … (L1.ⓑ{I}V))
-] /4 width=5 by lsuby_cpys_trans, lsuby_succ/ (**) (* full auto too slow *)
-qed.
-
-lemma lleq_flat: ∀I,L1,L2,V,T,d.
-                 L1 ⋕[V, d] L2 → L1 ⋕[T, d] L2 → L1 ⋕[ⓕ{I}V.T, d] L2.
-#I #L1 #L2 #V #T #d * #HL12 #IHV * #_ #IHT @conj // -HL12
-#X @conj #H elim (cpys_inv_flat1 … H) -H
-#W #U #HVW #HTU #H destruct
-elim (IHV W) -IHV elim (IHT U) -IHT
-/3 width=1 by cpys_flat/
-qed.
-
-lemma lleq_be: ∀L1,L2,U,dt. L1 ⋕[U, dt] L2 → ∀T,d,e. ⇧[d, e] T ≡ U →
-               d ≤ dt → dt ≤ d + e → L1 ⋕[U, d] L2.
-#L1 #L2 #U #dt * #HL12 #IH #T #d #e #HTU #Hddt #Hdtde @conj // -HL12
-#U0 elim (IH U0) -IH #H12 #H21 @conj
-#HU0 elim (cpys_up … HU0 … HTU) // -HU0 /4 width=5 by cpys_weak/
-qed-.
+(* Basic inversion lemmas ***************************************************)
 
-lemma lsuby_lleq_trans: ∀L2,L,T,d. L2 ⋕[T, d] L →
-                        ∀L1. L1 ⊑×[d, ∞] L2 → |L1| = |L2| → L1 ⋕[T, d] L.
-#L2 #L #T #d * #HL2 #IH #L1 #HL12 #H @conj // -HL2
-#U elim (IH U) -IH #Hdx #Hsn @conj #HTU
-[ @Hdx -Hdx -Hsn @(lsuby_cpys_trans … HTU) -HTU
-  /2 width=1 by lsuby_sym/ (**) (* full auto does not work *)
-| -H -Hdx /3 width=3 by lsuby_cpys_trans/
-]
+lemma lleq_ind: ∀R:relation4 ynat term lenv lenv. (
+                   ∀L1,L2,d,k. |L1| = |L2| → R d (⋆k) L1 L2
+                ) → (
+                   ∀L1,L2,d,i. |L1| = |L2| → yinj i < d → R d (#i) L1 L2
+                ) → (
+                   ∀I,L1,L2,K1,K2,V,d,i. d ≤ yinj i →
+                   ⇩[i] L1 ≡ K1.ⓑ{I}V → ⇩[i] L2 ≡ K2.ⓑ{I}V →
+                   K1 ≡[V, yinj O] K2 → R (yinj O) V K1 K2 → R d (#i) L1 L2
+                ) → (
+                   ∀L1,L2,d,i. |L1| = |L2| → |L1| ≤ i → |L2| ≤ i → R d (#i) L1 L2
+                ) → (
+                   ∀L1,L2,d,p. |L1| = |L2| → R d (§p) L1 L2
+                ) → (
+                   ∀a,I,L1,L2,V,T,d.
+                   L1 ≡[V, d]L2 → L1.ⓑ{I}V ≡[T, ⫯d] L2.ⓑ{I}V →
+                   R d V L1 L2 → R (⫯d) T (L1.ⓑ{I}V) (L2.ⓑ{I}V) → R d (ⓑ{a,I}V.T) L1 L2
+                ) → (
+                   ∀I,L1,L2,V,T,d.
+                   L1 ≡[V, d]L2 → L1 ≡[T, d] L2 →
+                   R d V L1 L2 → R d T L1 L2 → R d (ⓕ{I}V.T) L1 L2
+                ) →
+                ∀d,T,L1,L2. L1 ≡[T, d] L2 → R d T L1 L2.
+#R #H1 #H2 #H3 #H4 #H5 #H6 #H7 #d #T #L1 #L2 #H elim H -L1 -L2 -T -d /2 width=8 by/
 qed-.
 
-lemma lleq_lsuby_trans: ∀L,L1,T,d. L ⋕[T, d] L1 →
-                        ∀L2. L1 ⊑×[d, ∞] L2 → |L1| = |L2| → L ⋕[T, d] L2.
-/5 width=4 by lsuby_lleq_trans, lleq_sym, lsuby_sym/ qed-.
+lemma lleq_inv_bind: ∀a,I,L1,L2,V,T,d. L1 ≡[ⓑ{a,I}V.T, d] L2 →
+                     L1 ≡[V, d] L2 ∧ L1.ⓑ{I}V ≡[T, ⫯d] L2.ⓑ{I}V.
+/2 width=2 by llpx_sn_inv_bind/ qed-.
 
-lemma lleq_lsuby_repl: ∀L1,L2,T,d. L1 ⋕[T, d] L2 →
-                       ∀K1. K1 ⊑×[d, ∞] L1 → |K1| = |L1| →
-                       ∀K2. L2 ⊑×[d, ∞] K2 → |L2| = |K2| →
-                       K1 ⋕[T, d] K2.
-/3 width=4 by lleq_lsuby_trans, lsuby_lleq_trans/ qed-.
+lemma lleq_inv_flat: ∀I,L1,L2,V,T,d. L1 ≡[ⓕ{I}V.T, d] L2 →
+                     L1 ≡[V, d] L2 ∧ L1 ≡[T, d] L2.
+/2 width=2 by llpx_sn_inv_flat/ qed-.
 
 (* Basic forward lemmas *****************************************************)
 
-lemma lleq_fwd_length: ∀L1,L2,T,d. L1 ⋕[T, d] L2 → |L1| = |L2|.
-#L1 #L2 #T #d * //
+lemma lleq_fwd_length: ∀L1,L2,T,d. L1 ≡[T, d] L2 → |L1| = |L2|.
+/2 width=4 by llpx_sn_fwd_length/ qed-.
+
+lemma lleq_fwd_lref: ∀L1,L2,d,i. L1 ≡[#i, d] L2 →
+                     ∨∨ |L1| ≤ i ∧ |L2| ≤ i
+                      | yinj i < d
+                      | ∃∃I,K1,K2,V. ⇩[i] L1 ≡ K1.ⓑ{I}V &
+                                     ⇩[i] L2 ≡ K2.ⓑ{I}V &
+                                      K1 ≡[V, yinj 0] K2 & d ≤ yinj i.
+#L1 #L2 #d #i #H elim (llpx_sn_fwd_lref … H) /2 width=1/
+* /3 width=7 by or3_intro2, ex4_4_intro/
 qed-.
 
-lemma lleq_fwd_ldrop_sn: ∀L1,L2,T,d. L1 ⋕[d, T] L2 → ∀K1,i. ⇩[0, i] L1 ≡ K1 →
-                         ∃K2. ⇩[0, i] L2 ≡ K2.
-#L1 #L2 #T #d #H #K1 #i #HLK1 lapply (lleq_fwd_length … H) -H
-#HL12 lapply (ldrop_fwd_length_le2 … HLK1) -HLK1 /2 width=1 by ldrop_O1_le/
-qed-.
+lemma lleq_fwd_ldrop_sn: ∀L1,L2,T,d. L1 ≡[d, T] L2 → ∀K1,i. ⇩[i] L1 ≡ K1 →
+                         ∃K2. ⇩[i] L2 ≡ K2.
+/2 width=7 by llpx_sn_fwd_ldrop_sn/ qed-.
 
-lemma lleq_fwd_ldrop_dx: ∀L1,L2,T,d. L1 ⋕[d, T] L2 → ∀K2,i. ⇩[0, i] L2 ≡ K2 →
-                         ∃K1. ⇩[0, i] L1 ≡ K1.
-/3 width=6 by lleq_fwd_ldrop_sn, lleq_sym/ qed-.
+lemma lleq_fwd_ldrop_dx: ∀L1,L2,T,d. L1 ≡[d, T] L2 → ∀K2,i. ⇩[i] L2 ≡ K2 →
+                         ∃K1. ⇩[i] L1 ≡ K1.
+/2 width=7 by llpx_sn_fwd_ldrop_dx/ qed-.
 
 lemma lleq_fwd_bind_sn: ∀a,I,L1,L2,V,T,d.
-                        L1 ⋕[ⓑ{a,I}V.T, d] L2 → L1 ⋕[V, d] L2.
-#a #I #L1 #L2 #V #T #d * #HL12 #H @conj // -HL12
-#U elim (H (ⓑ{a,I}U.T)) -H
-#H1 #H2 @conj
-#H [ lapply (H1 ?) | lapply (H2 ?) ] -H1 -H2
-/2 width=1 by cpys_bind/ -H
-#H elim (cpys_inv_bind1 … H) -H
-#X #Y #H1 #H2 #H destruct //
-qed-.
+                        L1 ≡[ⓑ{a,I}V.T, d] L2 → L1 ≡[V, d] L2.
+/2 width=4 by llpx_sn_fwd_bind_sn/ qed-.
 
 lemma lleq_fwd_bind_dx: ∀a,I,L1,L2,V,T,d.
-                        L1 ⋕[ⓑ{a,I}V.T, d] L2 → L1.ⓑ{I}V ⋕[T, ⫯d] L2.ⓑ{I}V.
-#a #I #L1 #L2 #V #T #d * #HL12 #H @conj [ normalize // ] -HL12
-#U elim (H (ⓑ{a,I}V.U)) -H
-#H1 #H2 @conj
-#H [ lapply (H1 ?) | lapply (H2 ?) ] -H1 -H2
-/2 width=1 by cpys_bind/ -H
-#H elim (cpys_inv_bind1 … H) -H
-#X #Y #H1 #H2 #H destruct //
-qed-.
+                        L1 ≡[ⓑ{a,I}V.T, d] L2 → L1.ⓑ{I}V ≡[T, ⫯d] L2.ⓑ{I}V.
+/2 width=2 by llpx_sn_fwd_bind_dx/ qed-.
 
 lemma lleq_fwd_flat_sn: ∀I,L1,L2,V,T,d.
-                        L1 ⋕[ⓕ{I}V.T, d] L2 → L1 ⋕[V, d] L2.
-#I #L1 #L2 #V #T #d * #HL12 #H @conj // -HL12
-#U elim (H (ⓕ{I}U.T)) -H
-#H1 #H2 @conj
-#H [ lapply (H1 ?) | lapply (H2 ?) ] -H1 -H2
-/2 width=1 by cpys_flat/ -H
-#H elim (cpys_inv_flat1 … H) -H
-#X #Y #H1 #H2 #H destruct //
-qed-.
+                        L1 ≡[ⓕ{I}V.T, d] L2 → L1 ≡[V, d] L2.
+/2 width=3 by llpx_sn_fwd_flat_sn/ qed-.
 
 lemma lleq_fwd_flat_dx: ∀I,L1,L2,V,T,d.
-                        L1 ⋕[ⓕ{I}V.T, d] L2 → L1 ⋕[T, d] L2.
-#I #L1 #L2 #V #T #d * #HL12 #H @conj // -HL12
-#U elim (H (ⓕ{I}V.U)) -H
-#H1 #H2 @conj
-#H [ lapply (H1 ?) | lapply (H2 ?) ] -H1 -H2
-/2 width=1 by cpys_flat/ -H
-#H elim (cpys_inv_flat1 … H) -H
-#X #Y #H1 #H2 #H destruct //
+                        L1 ≡[ⓕ{I}V.T, d] L2 → L1 ≡[T, d] L2.
+/2 width=3 by llpx_sn_fwd_flat_dx/ qed-.
+
+(* Basic properties *********************************************************)
+
+lemma lleq_sort: ∀L1,L2,d,k. |L1| = |L2| → L1 ≡[⋆k, d] L2.
+/2 width=1 by llpx_sn_sort/ qed.
+
+lemma lleq_skip: ∀L1,L2,d,i. yinj i < d → |L1| = |L2| → L1 ≡[#i, d] L2.
+/2 width=1 by llpx_sn_skip/ qed.
+
+lemma lleq_lref: ∀I,L1,L2,K1,K2,V,d,i. d ≤ yinj i →
+                 ⇩[i] L1 ≡ K1.ⓑ{I}V → ⇩[i] L2 ≡ K2.ⓑ{I}V →
+                 K1 ≡[V, 0] K2 → L1 ≡[#i, d] L2.
+/2 width=9 by llpx_sn_lref/ qed.
+
+lemma lleq_free: ∀L1,L2,d,i. |L1| ≤ i → |L2| ≤ i → |L1| = |L2| → L1 ≡[#i, d] L2.
+/2 width=1 by llpx_sn_free/ qed.
+
+lemma lleq_gref: ∀L1,L2,d,p. |L1| = |L2| → L1 ≡[§p, d] L2.
+/2 width=1 by llpx_sn_gref/ qed.
+
+lemma lleq_bind: ∀a,I,L1,L2,V,T,d.
+                 L1 ≡[V, d] L2 → L1.ⓑ{I}V ≡[T, ⫯d] L2.ⓑ{I}V →
+                 L1 ≡[ⓑ{a,I}V.T, d] L2.
+/2 width=1 by llpx_sn_bind/ qed.
+
+lemma lleq_flat: ∀I,L1,L2,V,T,d.
+                 L1 ≡[V, d] L2 → L1 ≡[T, d] L2 → L1 ≡[ⓕ{I}V.T, d] L2.
+/2 width=1 by llpx_sn_flat/ qed.
+
+lemma lleq_refl: ∀d,T. reflexive … (lleq d T).
+/2 width=1 by llpx_sn_refl/ qed.
+
+lemma lleq_Y: ∀L1,L2,T. |L1| = |L2| → L1 ≡[T, ∞] L2.
+/2 width=1 by llpx_sn_Y/ qed.
+
+lemma lleq_sym: ∀d,T. symmetric … (lleq d T).
+#d #T #L1 #L2 #H @(lleq_ind … H) -d -T -L1 -L2
+/2 width=7 by lleq_sort, lleq_skip, lleq_lref, lleq_free, lleq_gref, lleq_bind, lleq_flat/
 qed-.
 
-(* Basic inversion lemmas ***************************************************)
+lemma lleq_ge_up: ∀L1,L2,U,dt. L1 ≡[U, dt] L2 →
+                  ∀T,d,e. ⇧[d, e] T ≡ U →
+                  dt ≤ d + e → L1 ≡[U, d] L2.
+/2 width=6 by llpx_sn_ge_up/ qed-.
+
+lemma lleq_ge: ∀L1,L2,T,d1. L1 ≡[T, d1] L2 → ∀d2. d1 ≤ d2 → L1 ≡[T, d2] L2.
+/2 width=3 by llpx_sn_ge/ qed-.
+
+lemma lleq_bind_O: ∀a,I,L1,L2,V,T. L1 ≡[V, 0] L2 → L1.ⓑ{I}V ≡[T, 0] L2.ⓑ{I}V →
+                   L1 ≡[ⓑ{a,I}V.T, 0] L2.
+/2 width=1 by llpx_sn_bind_O/ qed-.
 
-lemma lleq_inv_bind: ∀a,I,L1,L2,V,T,d. L1 ⋕[ⓑ{a,I}V.T, d] L2 →
-                     L1 ⋕[V, d] L2 ∧ L1.ⓑ{I}V ⋕[T, ⫯d] L2.ⓑ{I}V.
-/3 width=4 by lleq_fwd_bind_sn, lleq_fwd_bind_dx, conj/ qed-.
+(* Advancded properties on lazy pointwise exyensions ************************)
 
-lemma lleq_inv_flat: ∀I,L1,L2,V,T,d. L1 ⋕[ⓕ{I}V.T, d] L2 →
-                     L1 ⋕[V, d] L2 ∧ L1 ⋕[T, d] L2.
-/3 width=3 by lleq_fwd_flat_sn, lleq_fwd_flat_dx, conj/ qed-.
+lemma llpx_sn_lrefl: ∀R. (∀I,L. reflexive … (R I L)) →
+                     ∀L1,L2,T,d. L1 ≡[T, d] L2 → llpx_sn R d T L1 L2.
+/2 width=3 by llpx_sn_co/ qed-.