some advances on reduction

[helm.git] / matita / matita / contribs / lambdadelta / basic_2 / substitution / cpye_lift.ma

diff --git a/matita/matita/contribs/lambdadelta/basic_2/substitution/cpye_lift.ma b/matita/matita/contribs/lambdadelta/basic_2/substitution/cpye_lift.ma
index 1d494871ced9faa4362fb670d80cb57856aa6c88..3c0abe617b7db6e88b5f6c018bfc1ef8b6abc268 100644 (file)
--- a/matita/matita/contribs/lambdadelta/basic_2/substitution/cpye_lift.ma
+++ b/matita/matita/contribs/lambdadelta/basic_2/substitution/cpye_lift.ma
@@ -25,10 +25,10 @@ lemma cpye_subst: ∀I,G,L,K,V1,V2,W2,i,d,e. d ≤ yinj i → i < d + e →
                   ⇩[i] L ≡ K.ⓑ{I}V1 → ⦃G, K⦄ ⊢ V1 ▶*[O, ⫰(d+e-i)] 𝐍⦃V2⦄ →
                   ⇧[O, i+1] V2 ≡ W2 → ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃W2⦄.
 #I #G #L #K #V1 #V2 #W2 #i #d #e #Hdi #Hide #HLK *
-/4 width=13 by cpys_subst, cny_subst_aux, ldrop_fwd_drop2, conj/
+/4 width=13 by cpys_subst, cny_lift_subst, ldrop_fwd_drop2, conj/
 qed.
 
-lemma cpys_total: ∀G,L,T1,d,e. ∃T2. ⦃G, L⦄ ⊢ T1 ▶*[d, e] 𝐍⦃T2⦄.
+lemma cpye_total: ∀G,L,T1,d,e. ∃T2. ⦃G, L⦄ ⊢ T1 ▶*[d, e] 𝐍⦃T2⦄.
 #G #L #T1 @(fqup_wf_ind_eq … G L T1) -G -L -T1
 #Z #Y #X #IH #G #L * *
 [ #k #HG #HL #HT #d #e destruct -IH /2 width=2 by ex_intro/
@@ -64,7 +64,7 @@ lemma cpye_inv_lref1: ∀G,L,T2,d,e,i. ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃T2⦄
   /3 width=1 by or4_intro0, or4_intro1, or4_intro2, conj/
 | * #I #K #V1 #V2 #Hdi #Hide #HLK #HV12 #HVT2
     @or4_intro3 @(ex5_4_intro … HLK … HVT2) (**) (* explicit constructor *)
-    /4 width=13 by cny_inv_subst_aux, ldrop_fwd_drop2, conj/
+    /4 width=13 by cny_inv_lift_subst, ldrop_fwd_drop2, conj/
 ]
 qed-.
 
@@ -78,16 +78,92 @@ lemma cpye_inv_lref1_free: ∀G,L,T2,d,e,i. ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃
 elim (ylt_yle_false … H) //
 qed-.
 
+lemma cpye_inv_lref1_lget: ∀G,L,T2,d,e,i. ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃T2⦄ →
+                           ∀I,K,V1. ⇩[i] L ≡ K.ⓑ{I}V1 →
+                           ∨∨ d + e ≤ yinj i ∧ T2 = #i
+                            | yinj i < d ∧ T2 = #i
+                            | ∃∃V2. d ≤ yinj i & yinj i < d + e &
+                                    ⦃G, K⦄ ⊢ V1 ▶*[yinj 0, ⫰(d+e-yinj i)]  𝐍⦃V2⦄ &
+                                    ⇧[O, i+1] V2 ≡ T2.
+#G #L #T2 #d #e #i #H #I #K #V1 #HLK elim (cpye_inv_lref1 … H) -H *
+[ #H elim (lt_refl_false i) -T2 -d
+  @(lt_to_le_to_lt … H) -H /2 width=5 by ldrop_fwd_length_lt2/
+| /3 width=1 by or3_intro0, conj/
+| /3 width=1 by or3_intro1, conj/
+| #Z #Y #X1 #X2 #Hdi #Hide #HLY #HX12 #HXT2
+  lapply (ldrop_mono … HLY … HLK) -HLY -HLK #H destruct
+  /3 width=3 by or3_intro2, ex4_intro/
+]
+qed-.
+
+lemma cpye_inv_lref1_subst_ex: ∀G,L,T2,d,e,i. ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃T2⦄ →
+                               ∀I,K,V1. d ≤ yinj i → yinj i < d + e →
+                               ⇩[i] L ≡ K.ⓑ{I}V1 →
+                               ∃∃V2. ⦃G, K⦄ ⊢ V1 ▶*[yinj 0, ⫰(d+e-yinj i)]  𝐍⦃V2⦄ &
+                                     ⇧[O, i+1] V2 ≡ T2.
+#G #L #T2 #d #e #i #H #I #K #V1 #Hdi #Hide #HLK
+elim (cpye_inv_lref1_lget … H … HLK) -H * /2 width=3 by ex2_intro/
+#H elim (ylt_yle_false … H) //
+qed-.
+
 lemma cpye_inv_lref1_subst: ∀G,L,T2,d,e,i. ⦃G, L⦄ ⊢ #i ▶*[d, e] 𝐍⦃T2⦄ →
                             ∀I,K,V1,V2. d ≤ yinj i → yinj i < d + e →
                             ⇩[i] L ≡ K.ⓑ{I}V1 → ⇧[O, i+1] V2 ≡ T2 →
                             ⦃G, K⦄ ⊢ V1 ▶*[yinj 0, ⫰(d+e-yinj i)]  𝐍⦃V2⦄.
-#G #L #T2 #d #e #i #H #I #K #V1 #V2 #Hdi #Hide #HLK #HVT2 elim (cpye_inv_lref1 … H) -H *
-[ #H elim (lt_refl_false i) -V2 -T2 -d
-  @(lt_to_le_to_lt … H) -H /2 width=5 by ldrop_fwd_length_lt2/
-|2,3: #H elim (ylt_yle_false … H) //
-| #Z #Y #X1 #X2 #_ #_ #HLY #HX12 #HXT2
-  lapply (ldrop_mono … HLY … HLK) -HLY -HLK #H destruct
-  lapply (lift_inj … HXT2 … HVT2) -HXT2 -HVT2 #H destruct //
-]
+#G #L #T2 #d #e #i #H #I #K #V1 #V2 #Hdi #Hide #HLK #HVT2
+elim (cpye_inv_lref1_subst_ex … H … HLK) -H -HLK //
+#X2 #H0 #HXT2 lapply (lift_inj … HXT2 … HVT2) -HXT2 -HVT2 #H destruct //
+qed-.
+
+(* Inversion lemmas on relocation *******************************************)
+
+lemma cpye_inv_lift1_le: ∀G,L,U1,U2,dt,et. ⦃G, L⦄ ⊢ U1 ▶*[dt, et] 𝐍⦃U2⦄ →
+                         ∀K,s,d,e. ⇩[s, d, e] L ≡ K → ∀T1. ⇧[d, e] T1 ≡ U1 →
+                         dt + et ≤ d →
+                         ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶*[dt, et] 𝐍⦃T2⦄ & ⇧[d, e] T2 ≡ U2.
+#G #L #U1 #U2 #dt #et * #HU12 #HU2 #K #s #d #e #HLK #T1 #HTU1 #Hdetd
+elim (cpys_inv_lift1_le … HU12 … HLK … HTU1) -U1 // #T2 #HT12 #HTU2
+lapply (cny_inv_lift_le … HU2 … HLK … HTU2 ?) -L
+/3 width=3 by ex2_intro, conj/
+qed-.
+
+lemma cpye_inv_lift1_be: ∀G,L,U1,U2,dt,et. ⦃G, L⦄ ⊢ U1 ▶*[dt, et] 𝐍⦃U2⦄ →
+                         ∀K,s,d,e. ⇩[s, d, e] L ≡ K → ∀T1. ⇧[d, e] T1 ≡ U1 →
+                         dt ≤ d → yinj d + e ≤ dt + et →
+                         ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶*[dt, et - e] 𝐍⦃T2⦄ & ⇧[d, e] T2 ≡ U2.
+#G #L #U1 #U2 #dt #et * #HU12 #HU2 #K #s #d #e #HLK #T1 #HTU1 #Hdtd #Hdedet
+elim (cpys_inv_lift1_be … HU12 … HLK … HTU1) -U1 // #T2 #HT12 #HTU2
+lapply (cny_inv_lift_be … HU2 … HLK … HTU2 ? ?) -L
+/3 width=3 by ex2_intro, conj/
+qed-.
+
+lemma cpye_inv_lift1_ge: ∀G,L,U1,U2,dt,et. ⦃G, L⦄ ⊢ U1 ▶*[dt, et] 𝐍⦃U2⦄ →
+                         ∀K,s,d,e. ⇩[s, d, e] L ≡ K → ∀T1. ⇧[d, e] T1 ≡ U1 →
+                         yinj d + e ≤ dt →
+                         ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶*[dt - e, et] 𝐍⦃T2⦄ & ⇧[d, e] T2 ≡ U2.
+#G #L #U1 #U2 #dt #et * #HU12 #HU2 #K #s #d #e #HLK #T1 #HTU1 #Hdedt
+elim (cpys_inv_lift1_ge … HU12 … HLK … HTU1) -U1 // #T2 #HT12 #HTU2
+lapply (cny_inv_lift_ge … HU2 … HLK … HTU2 ?) -L
+/3 width=3 by ex2_intro, conj/
+qed-.
+
+lemma cpye_inv_lift1_ge_up: ∀G,L,U1,U2,dt,et. ⦃G, L⦄ ⊢ U1 ▶*[dt, et] 𝐍⦃U2⦄ →
+                            ∀K,s,d,e. ⇩[s, d, e] L ≡ K → ∀T1. ⇧[d, e] T1 ≡ U1 →
+                            d ≤ dt → dt ≤ yinj d + e → yinj d + e ≤ dt + et →
+                            ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶*[d, dt + et - (yinj d + e)] 𝐍⦃T2⦄ &
+                                 ⇧[d, e] T2 ≡ U2.
+#G #L #U1 #U2 #dt #et * #HU12 #HU2 #K #s #d #e #HLK #T1 #HTU1 #Hddt #Hdtde #Hdedet
+elim (cpys_inv_lift1_ge_up … HU12 … HLK … HTU1) -U1 // #T2 #HT12 #HTU2
+lapply (cny_inv_lift_ge_up … HU2 … HLK … HTU2 ? ? ?) -L
+/3 width=3 by ex2_intro, conj/
+qed-.
+
+lemma cpye_inv_lift1_subst: ∀G,L,W1,W2,d,e. ⦃G, L⦄ ⊢ W1 ▶*[d, e] 𝐍⦃W2⦄ →
+                            ∀K,V1,i. ⇩[i+1] L ≡ K → ⇧[O, i+1] V1 ≡ W1 →
+                            d ≤ yinj i → i < d + e →
+                            ∃∃V2.  ⦃G, K⦄ ⊢ V1 ▶*[O, ⫰(d+e-i)] 𝐍⦃V2⦄ & ⇧[O, i+1] V2 ≡ W2.
+#G #L #W1 #W2 #d #e * #HW12 #HW2 #K #V1 #i #HLK #HVW1 #Hdi #Hide
+elim (cpys_inv_lift1_subst … HW12 … HLK … HVW1) -W1 // #V2 #HV12 #HVW2
+lapply (cny_inv_lift_subst … HLK HW2 HVW2) -L
+/3 width=3 by ex2_intro, conj/
 qed-.