2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department of the University of Bologna, Italy.
7 ||A|| This file is distributed under the terms of the
8 \ / GNU General Public License Version 2
10 V_______________________________________________________________ *)
12 include "lambda-delta/substitution/drop_drop.ma".
13 include "lambda-delta/substitution/tps.ma".
15 (* PARTIAL SUBSTITUTION ON TERMS ********************************************)
17 (* Relocation properties ****************************************************)
19 lemma tps_lift_le: ∀K,T1,T2,dt,et. K ⊢ T1 [dt, et] ≫ T2 →
20 ∀L,U1,U2,d,e. ↓[d, e] L ≡ K →
21 ↑[d, e] T1 ≡ U1 → ↑[d, e] T2 ≡ U2 →
24 #K #T1 #T2 #dt #et #H elim H -H K T1 T2 dt et
25 [ #K #k #dt #et #L #U1 #U2 #d #e #_ #H1 #H2 #_
26 lapply (lift_mono … H1 … H2) -H1 H2 #H destruct -U1 //
27 | #K #i #dt #et #L #U1 #U2 #d #e #_ #H1 #H2 #_
28 lapply (lift_mono … H1 … H2) -H1 H2 #H destruct -U1 //
29 | #K #KV #V #V1 #V2 #i #dt #et #Hdti #Hidet #HKV #_ #HV12 #IHV12 #L #U1 #U2 #d #e #HLK #H #HVU2 #Hdetd
30 lapply (lt_to_le_to_lt … Hidet … Hdetd) #Hid
31 lapply (lift_inv_lref1_lt … H … Hid) -H #H destruct -U1;
32 elim (lift_trans_ge … HV12 … HVU2 ?) -HV12 HVU2 V2 // <minus_plus #V2 #HV12 #HVU2
33 elim (drop_trans_le … HLK … HKV ?) -HLK HKV K /2/ #X #HLK #H
34 elim (drop_inv_skip2 … H ?) -H /2/ -Hid #K #W #HKV #HVW #H destruct -X
35 @tps_subst [4,5,6,8: // |1,2,3: skip | @IHV12 /2 width=6/ ] (**) (* explicit constructor *)
36 | #K #I #V1 #V2 #T1 #T2 #dt #et #_ #_ #IHV12 #IHT12 #L #U1 #U2 #d #e #HLK #H1 #H2 #Hdetd
37 elim (lift_inv_bind1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
38 elim (lift_inv_bind1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct -U1 U2;
39 @tps_bind [ /2 width=6/ | @IHT12 [3,4,5: /2/ |1,2: skip | /2/ ] ] (**) (* /3 width=6/ is too slow, arith3 needed to avoid crash *)
40 | #K #I #V1 #V2 #T1 #T2 #dt #et #_ #_ #IHV12 #IHT12 #L #U1 #U2 #d #e #HLK #H1 #H2 #Hdetd
41 elim (lift_inv_flat1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
42 elim (lift_inv_flat1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct -U1 U2;
47 lemma tps_lift_ge: ∀K,T1,T2,dt,et. K ⊢ T1 [dt, et] ≫ T2 →
48 ∀L,U1,U2,d,e. ↓[d, e] L ≡ K →
49 ↑[d, e] T1 ≡ U1 → ↑[d, e] T2 ≡ U2 →
51 L ⊢ U1 [dt + e, et] ≫ U2.
52 #K #T1 #T2 #dt #et #H elim H -H K T1 T2 dt et
53 [ #K #k #dt #et #L #U1 #U2 #d #e #_ #H1 #H2 #_
54 lapply (lift_mono … H1 … H2) -H1 H2 #H destruct -U1 //
55 | #K #i #dt #et #L #U1 #U2 #d #e #_ #H1 #H2 #_
56 lapply (lift_mono … H1 … H2) -H1 H2 #H destruct -U1 //
57 | #K #KV #V #V1 #V2 #i #dt #et #Hdti #Hidet #HKV #HV1 #HV12 #_ #L #U1 #U2 #d #e #HLK #H #HVU2 #Hddt
58 <(arith_c1x ? ? ? e) in HV1 #HV1 (**) (* explicit athmetical rewrite and ?'s *)
59 lapply (transitive_le … Hddt … Hdti) -Hddt #Hid
60 lapply (lift_inv_lref1_ge … H … Hid) -H #H destruct -U1;
61 lapply (lift_trans_be … HV12 … HVU2 ? ?) -HV12 HVU2 V2 /2/ >plus_plus_comm_23 #HV1U2
62 lapply (drop_trans_ge_comm … HLK … HKV ?) -HLK HKV K // -Hid #HLKV
63 @tps_subst [4,5: /2/ |6,7,8: // |1,2,3: skip ] (**) (* /3 width=8/ is too slow *)
64 | #K #I #V1 #V2 #T1 #T2 #dt #et #_ #_ #IHV12 #IHT12 #L #U1 #U2 #d #e #HLK #H1 #H2 #Hddt
65 elim (lift_inv_bind1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
66 elim (lift_inv_bind1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct -U1 U2;
67 @tps_bind [ /2 width=5/ | /3 width=5/ ] (**) (* explicit constructor *)
68 | #K #I #V1 #V2 #T1 #T2 #dt #et #_ #_ #IHV12 #IHT12 #L #U1 #U2 #d #e #HLK #H1 #H2 #Hddt
69 elim (lift_inv_flat1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
70 elim (lift_inv_flat1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct -U1 U2;
75 lemma tps_inv_lift1_le: ∀L,U1,U2,dt,et. L ⊢ U1 [dt, et] ≫ U2 →
76 ∀K,d,e. ↓[d, e] L ≡ K → ∀T1. ↑[d, e] T1 ≡ U1 →
78 ∃∃T2. K ⊢ T1 [dt, et] ≫ T2 & ↑[d, e] T2 ≡ U2.
79 #L #U1 #U2 #dt #et #H elim H -H L U1 U2 dt et
80 [ #L #k #dt #et #K #d #e #_ #T1 #H #_
81 lapply (lift_inv_sort2 … H) -H #H destruct -T1 /2/
82 | #L #i #dt #et #K #d #e #_ #T1 #H #_
83 elim (lift_inv_lref2 … H) -H * #Hid #H destruct -T1 /3/
84 | #L #KV #V #V1 #V2 #i #dt #et #Hdti #Hidet #HLKV #_ #HV12 #IHV12 #K #d #e #HLK #T1 #H #Hdetd
85 lapply (lt_to_le_to_lt … Hidet … Hdetd) #Hid
86 lapply (lift_inv_lref2_lt … H … Hid) -H #H destruct -T1;
87 elim (drop_conf_lt … HLK … HLKV ?) -HLK HLKV L // #L #W #HKL #HKVL #HWV
88 elim (IHV12 … HKVL … HWV ?) -HKVL HWV /2/ -Hdetd #W1 #HW1 #HWV1
89 elim (lift_trans_le … HWV1 … HV12 ?) -HWV1 HV12 V1 // >arith_a2 /3 width=6/
90 | #L #I #V1 #V2 #U1 #U2 #dt #et #_ #_ #IHV12 #IHU12 #K #d #e #HLK #X #H #Hdetd
91 elim (lift_inv_bind2 … H) -H #W1 #T1 #HWV1 #HTU1 #H destruct -X;
92 elim (IHV12 … HLK … HWV1 ?) -IHV12 //
93 elim (IHU12 … HTU1 ?) -IHU12 HTU1 [3: /2/ |4: @drop_skip // |2: skip ] -HLK HWV1 Hdetd /3 width=5/ (**) (* just /3 width=5/ is too slow *)
94 | #L #I #V1 #V2 #U1 #U2 #dt #et #_ #_ #IHV12 #IHU12 #K #d #e #HLK #X #H #Hdetd
95 elim (lift_inv_flat2 … H) -H #W1 #T1 #HWV1 #HTU1 #H destruct -X;
96 elim (IHV12 … HLK … HWV1 ?) -IHV12 HWV1 //
97 elim (IHU12 … HLK … HTU1 ?) -IHU12 HLK HTU1 // /3 width=5/
101 lemma tps_inv_lift1_ge: ∀L,U1,U2,dt,et. L ⊢ U1 [dt, et] ≫ U2 →
102 ∀K,d,e. ↓[d, e] L ≡ K → ∀T1. ↑[d, e] T1 ≡ U1 →
104 ∃∃T2. K ⊢ T1 [dt - e, et] ≫ T2 & ↑[d, e] T2 ≡ U2.
105 #L #U1 #U2 #dt #et #H elim H -H L U1 U2 dt et
106 [ #L #k #dt #et #K #d #e #_ #T1 #H #_
107 lapply (lift_inv_sort2 … H) -H #H destruct -T1 /2/
108 | #L #i #dt #et #K #d #e #_ #T1 #H #_
109 elim (lift_inv_lref2 … H) -H * #Hid #H destruct -T1 /3/
110 | #L #KV #V #V1 #V2 #i #dt #et #Hdti #Hidet #HLKV #HV1 #HV12 #_ #K #d #e #HLK #T1 #H #Hdedt
111 lapply (transitive_le … Hdedt … Hdti) #Hdei
112 lapply (plus_le_weak … Hdedt) -Hdedt #Hedt
113 lapply (plus_le_weak … Hdei) #Hei
114 <(arith_h1 ? ? ? e ? ?) in HV1 // #HV1
115 lapply (lift_inv_lref2_ge … H … Hdei) -H #H destruct -T1;
116 lapply (drop_conf_ge … HLK … HLKV ?) -HLK HLKV L // #HKV
117 elim (lift_split … HV12 d (i - e + 1) ? ? ?) -HV12; [2,3,4: normalize /2/ ] -Hdei >arith_e2 // #V0 #HV10 #HV02
119 [2: @tps_subst [4: /2/ |6,7,8: // |1,2,3: skip |5: @arith5 // ]
122 ] (**) (* explicitc constructors *)
123 | #L #I #V1 #V2 #U1 #U2 #dt #et #_ #_ #IHV12 #IHU12 #K #d #e #HLK #X #H #Hdetd
124 elim (lift_inv_bind2 … H) -H #W1 #T1 #HWV1 #HTU1 #H destruct -X;
125 lapply (plus_le_weak … Hdetd) #Hedt
126 elim (IHV12 … HLK … HWV1 ?) -IHV12 // #W2 #HW12 #HWV2
127 elim (IHU12 … HTU1 ?) -IHU12 HTU1 [4: @drop_skip // |2: skip |3: /2/ ]
128 <plus_minus // /3 width=5/
129 | #L #I #V1 #V2 #U1 #U2 #dt #et #_ #_ #IHV12 #IHU12 #K #d #e #HLK #X #H #Hdetd
130 elim (lift_inv_flat2 … H) -H #W1 #T1 #HWV1 #HTU1 #H destruct -X;
131 elim (IHV12 … HLK … HWV1 ?) -IHV12 HWV1 //
132 elim (IHU12 … HLK … HTU1 ?) -IHU12 HLK HTU1 // /3 width=5/
136 lemma tps_inv_lift1_eq: ∀L,U1,U2,d,e.
137 L ⊢ U1 [d, e] ≫ U2 → ∀T1. ↑[d, e] T1 ≡ U1 → U1 = U2.
138 #L #U1 #U2 #d #e #H elim H -H L U1 U2 d e
141 | #L #K #V #V1 #V2 #i #d #e #Hdi #Hide #_ #_ #_ #_ #T1 #H
142 elim (lift_inv_lref2 … H) -H * #H
143 [ lapply (le_to_lt_to_lt … Hdi … H) -Hdi H #H
144 elim (lt_refl_false … H)
145 | lapply (lt_to_le_to_lt … Hide … H) -Hide H #H
146 elim (lt_refl_false … H)
148 | #L #I #V1 #V2 #T1 #T2 #d #e #_ #_ #IHV12 #IHT12 #X #HX
149 elim (lift_inv_bind2 … HX) -HX #V #T #HV1 #HT1 #H destruct -X
151 | #L #I #V1 #V2 #T1 #T2 #d #e #_ #_ #IHV12 #IHT12 #X #HX
152 elim (lift_inv_flat2 … HX) -HX #V #T #HV1 #HT1 #H destruct -X
157 Theorem subst0_gen_lift_ge : (u,t1,x:?; i,h,d:?) (subst0 i u (lift h d t1) x) ->
159 (EX t2 | x = (lift h d t2) & (subst0 (minus i h) u t1 t2)).
161 Theorem subst0_gen_lift_rev_ge: (t1,v,u2:?; i,h,d:?)
162 (subst0 i v t1 (lift h d u2)) ->
164 (EX u1 | (subst0 (minus i h) v u1 u2) &
169 Theorem subst0_gen_lift_rev_lelt: (t1,v,u2:?; i,h,d:?)
170 (subst0 i v t1 (lift h d u2)) ->
171 (le d i) -> (lt i (plus d h)) ->
172 (EX u1 | t1 = (lift (minus (plus d h) (S i)) (S i) u1)).