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4 (* ||A|| A project by Andrea Asperti *)
6 (* ||I|| Developers: *)
7 (* ||T|| The HELM team. *)
8 (* ||A|| http://helm.cs.unibo.it *)
10 (* \ / This file is distributed under the terms of the *)
11 (* v GNU General Public License Version 2 *)
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15 include "basic_2/substitution/drop_drop.ma".
16 include "basic_2/substitution/cpy.ma".
18 (* CONTEXT-SENSITIVE EXTENDED ORDINARY SUBSTITUTION FOR TERMS ***************)
20 (* Properties on relocation *************************************************)
22 (* Basic_1: was: subst1_lift_lt *)
23 lemma cpy_lift_le: ∀G,K,T1,T2,lt,mt. ⦃G, K⦄ ⊢ T1 ▶[lt, mt] T2 →
24 ∀L,U1,U2,s,l,m. ⬇[s, l, m] L ≡ K →
25 ⬆[l, m] T1 ≡ U1 → ⬆[l, m] T2 ≡ U2 →
26 lt + mt ≤ l → ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2.
27 #G #K #T1 #T2 #lt #mt #H elim H -G -K -T1 -T2 -lt -mt
28 [ #I #G #K #lt #mt #L #U1 #U2 #s #l #m #_ #H1 #H2 #_
29 >(lift_mono … H1 … H2) -H1 -H2 //
30 | #I #G #K #KV #V #W #i #lt #mt #Hlti #Hilmt #HKV #HVW #L #U1 #U2 #s #l #m #HLK #H #HWU2 #Hlmtl
31 lapply (ylt_yle_trans … Hlmtl … Hilmt) -Hlmtl #Hil
32 lapply (lift_inv_lref1_lt … H … Hil) -H #H destruct
33 elim (lift_trans_ge … HVW … HWU2) -W /2 width=1 by ylt_fwd_le_succ1/
34 <yplus_inj >yplus_SO2 >yminus_succ2 #W #HVW #HWU2
35 elim (drop_trans_le … HLK … HKV) -K /2 width=2 by ylt_fwd_le/ #X #HLK #H
36 elim (drop_inv_skip2 … H) -H /2 width=1 by ylt_to_minus/ -Hil #K #Y #_ #HVY
37 >(lift_mono … HVY … HVW) -Y -HVW #H destruct /2 width=5 by cpy_subst/
38 | #a #I #G #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hlmtl
39 elim (lift_inv_bind1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
40 elim (lift_inv_bind1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
41 /4 width=7 by cpy_bind, drop_skip, yle_succ/
42 | #G #I #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hlmtl
43 elim (lift_inv_flat1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
44 elim (lift_inv_flat1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
45 /3 width=7 by cpy_flat/
49 lemma cpy_lift_be: ∀G,K,T1,T2,lt,mt. ⦃G, K⦄ ⊢ T1 ▶[lt, mt] T2 →
50 ∀L,U1,U2,s,l,m. ⬇[s, l, m] L ≡ K →
51 ⬆[l, m] T1 ≡ U1 → ⬆[l, m] T2 ≡ U2 →
52 lt ≤ l → l ≤ lt + mt → ⦃G, L⦄ ⊢ U1 ▶[lt, mt + m] U2.
53 #G #K #T1 #T2 #lt #mt #H elim H -G -K -T1 -T2 -lt -mt
54 [ #I #G #K #lt #mt #L #U1 #U2 #s #l #m #_ #H1 #H2 #_ #_
55 >(lift_mono … H1 … H2) -H1 -H2 //
56 | #I #G #K #KV #V #W #i #lt #mt #Hlti #Hilmt #HKV #HVW #L #U1 #U2 #s #l #m #HLK #H #HWU2 #Hltl #_
57 elim (lift_inv_lref1 … H) -H * #Hil #H destruct
59 lapply (ylt_yle_trans … (lt+mt+m) … Hilmt) // -Hilmt #Hilmtm
60 elim (lift_trans_ge … HVW … HWU2) -W <yplus_inj >yplus_SO2
61 [2: >yplus_O1 /2 width=1 by ylt_fwd_le_succ1/ ] >yminus_succ2 #W #HVW #HWU2
62 elim (drop_trans_le … HLK … HKV) -K /2 width=1 by ylt_fwd_le/ #X #HLK #H
63 elim (drop_inv_skip2 … H) -H /2 width=1 by ylt_to_minus/ -Hil #K #Y #_ #HVY
64 >(lift_mono … HVY … HVW) -V #H destruct /2 width=5 by cpy_subst/
66 lapply (yle_trans … Hltl … Hil) -Hltl #Hlti
67 lapply (lift_trans_be … HVW … HWU2 ? ?) -W /2 width=1 by yle_succ_dx/ >plus_plus_comm_23 #HVU2
68 lapply (drop_trans_ge_comm … HLK … HKV ?) -K // -Hil
69 /3 width=5 by cpy_subst, drop_inv_gen, monotonic_ylt_plus_dx, yle_plus_dx1_trans/
71 | #a #I #G #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hltl #Hllmt
72 elim (lift_inv_bind1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
73 elim (lift_inv_bind1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
74 /4 width=7 by cpy_bind, drop_skip, yle_succ/
75 | #I #G #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hlmtl
76 elim (lift_inv_flat1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
77 elim (lift_inv_flat1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
78 /3 width=7 by cpy_flat/
82 (* Basic_1: was: subst1_lift_ge *)
83 lemma cpy_lift_ge: ∀G,K,T1,T2,lt,mt. ⦃G, K⦄ ⊢ T1 ▶[lt, mt] T2 →
84 ∀L,U1,U2,s,l,m. ⬇[s, l, m] L ≡ K →
85 ⬆[l, m] T1 ≡ U1 → ⬆[l, m] T2 ≡ U2 →
86 l ≤ lt → ⦃G, L⦄ ⊢ U1 ▶[lt+m, mt] U2.
87 #G #K #T1 #T2 #lt #mt #H elim H -G -K -T1 -T2 -lt -mt
88 [ #I #G #K #lt #mt #L #U1 #U2 #s #l #m #_ #H1 #H2 #_
89 >(lift_mono … H1 … H2) -H1 -H2 //
90 | #I #G #K #KV #V #W #i #lt #mt #Hlti #Hilmt #HKV #HVW #L #U1 #U2 #s #l #m #HLK #H #HWU2 #Hllt
91 lapply (yle_trans … Hllt … Hlti) -Hllt #Hil
92 lapply (lift_inv_lref1_ge … H … Hil) -H #H destruct
93 lapply (lift_trans_be … HVW … HWU2 ? ?) -W /2 width=1 by yle_succ_dx/ >plus_plus_comm_23 #HVU2
94 lapply (drop_trans_ge_comm … HLK … HKV ?) -K // -Hil
95 /3 width=5 by cpy_subst, drop_inv_gen, monotonic_ylt_plus_dx, monotonic_yle_plus_dx/
96 | #a #I #G #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hllt
97 elim (lift_inv_bind1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
98 elim (lift_inv_bind1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
99 /4 width=6 by cpy_bind, drop_skip, yle_succ/
100 | #I #G #K #V1 #V2 #T1 #T2 #lt #mt #_ #_ #IHV12 #IHT12 #L #U1 #U2 #s #l #m #HLK #H1 #H2 #Hllt
101 elim (lift_inv_flat1 … H1) -H1 #VV1 #TT1 #HVV1 #HTT1 #H1
102 elim (lift_inv_flat1 … H2) -H2 #VV2 #TT2 #HVV2 #HTT2 #H2 destruct
103 /3 width=6 by cpy_flat/
107 (* Inversion lemmas on relocation *******************************************)
109 (* Basic_1: was: subst1_gen_lift_lt *)
110 lemma cpy_inv_lift1_le: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
111 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
113 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[lt, mt] T2 & ⬆[l, m] T2 ≡ U2.
114 #G #L #U1 #U2 #lt #mt #H elim H -G -L -U1 -U2 -lt -mt
115 [ * #i #G #L #lt #mt #K #s #l #m #_ #T1 #H #_
116 [ lapply (lift_inv_sort2 … H) -H #H destruct /2 width=3 by ex2_intro/
117 | elim (lift_inv_lref2 … H) -H * #Hil #H destruct /3 width=3 by lift_lref_ge_minus, lift_lref_lt, ex2_intro/
118 | lapply (lift_inv_gref2 … H) -H #H destruct /2 width=3 by ex2_intro/
120 | #I #G #L #KV #V #W #i #lt #mt #Hlti #Hilmt #HLKV #HVW #K #s #l #m #HLK #T1 #H #Hlmtl
121 lapply (ylt_yle_trans … Hlmtl … Hilmt) -Hlmtl #Hil
122 lapply (lift_inv_lref2_lt … H … Hil) -H #H destruct
123 elim (drop_conf_lt … HLK … HLKV) -L // #L #U #HKL #_ #HUV
124 elim (lift_trans_le … HUV … HVW) -V // >minus_plus <plus_minus_m_m //
125 <yminus_succ2 <yplus_inj >yplus_SO2 >ymax_pre_sn /2 width=1 by ylt_fwd_le_succ1/ -Hil
126 /3 width=5 by cpy_subst, ex2_intro/
127 | #a #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hlmtl
128 elim (lift_inv_bind2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
129 elim (IHW12 … HLK … HVW1) -IHW12 // #V2 #HV12 #HVW2
130 elim (IHU12 … HTU1) -IHU12 -HTU1
131 /3 width=6 by cpy_bind, yle_succ, drop_skip, lift_bind, ex2_intro/
132 | #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hlmtl
133 elim (lift_inv_flat2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
134 elim (IHW12 … HLK … HVW1) -W1 //
135 elim (IHU12 … HLK … HTU1) -U1 -HLK
136 /3 width=5 by cpy_flat, lift_flat, ex2_intro/
140 lemma cpy_inv_lift1_be: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
141 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
142 lt ≤ l → l + m ≤ lt + mt →
143 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[lt, mt-m] T2 & ⬆[l, m] T2 ≡ U2.
144 #G #L #U1 #U2 #lt #mt #H elim H -G -L -U1 -U2 -lt -mt
145 [ * #i #G #L #lt #mt #K #s #l #m #_ #T1 #H #_ #_
146 [ lapply (lift_inv_sort2 … H) -H #H destruct /2 width=3 by ex2_intro/
147 | elim (lift_inv_lref2 … H) -H * #Hil #H destruct /3 width=3 by lift_lref_ge_minus, lift_lref_lt, ex2_intro/
148 | lapply (lift_inv_gref2 … H) -H #H destruct /2 width=3 by ex2_intro/
150 | #I #G #L #KV #V #W #i #x #mt #Hlti #Hilmt #HLKV #HVW #K #s #l #m #HLK #T1 #H #Hltl #Hlmlmt
151 elim (yle_inv_inj2 … Hlti) -Hlti #lt #Hlti #H destruct
152 lapply (yle_fwd_plus_yge … Hltl Hlmlmt) #Hmmt
153 elim (lift_inv_lref2 … H) -H * #Hil #H destruct [ -Hltl -Hilmt | -Hlti -Hlmlmt ]
154 [ lapply (ylt_yle_trans i l (lt+(mt-m)) ? ?) //
155 [ >yplus_minus_assoc_inj /2 width=1 by yle_plus1_to_minus_inj2/ ] -Hlmlmt #Hilmtm
156 elim (drop_conf_lt … HLK … HLKV) -L // #L #U #HKL #_ #HUV
157 elim (lift_trans_le … HUV … HVW) -V //
158 <yminus_succ2 <yplus_inj >yplus_SO2 >ymax_pre_sn /2 width=1 by ylt_fwd_le_succ1/ -Hil
159 /4 width=5 by cpy_subst, ex2_intro, yle_inj/
160 | elim (yle_inv_plus_inj2 … Hil) #Hlim #Hmi
161 lapply (yle_inv_inj … Hmi) -Hmi #Hmi
162 lapply (yle_trans … Hltl (i-m) ?) // -Hltl #Hltim
163 lapply (drop_conf_ge … HLK … HLKV ?) -L // #HKV
164 elim (lift_split … HVW l (i-m+1)) -HVW [2,3,4: /2 width=1 by yle_succ_dx, le_S_S/ ] -Hil -Hlim
165 #V1 #HV1 >plus_minus // <minus_minus /2 width=1 by le_S/ <minus_n_n <plus_n_O #H
166 @(ex2_intro … H) @(cpy_subst … HKV HV1) // (**) (* explicit constructor *)
167 >yplus_minus_assoc_inj /3 width=1 by monotonic_ylt_minus_dx, yle_inj/
169 | #a #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hltl #Hlmlmt
170 elim (lift_inv_bind2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
171 elim (IHW12 … HLK … HVW1) -IHW12 // #V2 #HV12 #HVW2
172 elim (IHU12 … HTU1) -U1
173 /3 width=6 by cpy_bind, drop_skip, lift_bind, yle_succ, ex2_intro/
174 | #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hltl #Hlmlmt
175 elim (lift_inv_flat2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
176 elim (IHW12 … HLK … HVW1) -W1 //
177 elim (IHU12 … HLK … HTU1) -U1 -HLK //
178 /3 width=5 by cpy_flat, lift_flat, ex2_intro/
182 (* Basic_1: was: subst1_gen_lift_ge *)
183 lemma cpy_inv_lift1_ge: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
184 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
186 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[lt-m, mt] T2 & ⬆[l, m] T2 ≡ U2.
187 #G #L #U1 #U2 #lt #mt #H elim H -G -L -U1 -U2 -lt -mt
188 [ * #i #G #L #lt #mt #K #s #l #m #_ #T1 #H #_
189 [ lapply (lift_inv_sort2 … H) -H #H destruct /2 width=3 by ex2_intro/
190 | elim (lift_inv_lref2 … H) -H * #Hil #H destruct /3 width=3 by lift_lref_ge_minus, lift_lref_lt, ex2_intro/
191 | lapply (lift_inv_gref2 … H) -H #H destruct /2 width=3 by ex2_intro/
193 | #I #G #L #KV #V #W #i #lt #mt #Hlti #Hilmt #HLKV #HVW #K #s #l #m #HLK #T1 #H #Hlmlt
194 lapply (yle_trans … Hlmlt … Hlti) #Hlmi
195 elim (yle_inv_plus_inj2 … Hlmlt) -Hlmlt #_ #Hmlt
196 elim (yle_inv_plus_inj2 … Hlmi) #Hlim #Hmi
197 lapply (yle_inv_inj … Hmi) -Hmi #Hmi
198 lapply (lift_inv_lref2_ge … H ?) -H // #H destruct
199 lapply (drop_conf_ge … HLK … HLKV ?) -L // #HKV
200 elim (lift_split … HVW l (i-m+1)) -HVW [2,3,4: /3 width=1 by yle_succ, yle_pred_sn, le_S_S/ ] -Hlmi -Hlim
201 #V0 #HV10 >plus_minus // <minus_minus /3 width=1 by le_S/ <minus_n_n <plus_n_O #H
202 @(ex2_intro … H) @(cpy_subst … HKV HV10) (**) (* explicit constructor *)
203 [ /2 width=1 by monotonic_yle_minus_dx/
204 | <yminus_inj <yplus_minus_comm_inj // /3 width=1 by monotonic_ylt_minus_dx, yle_inj/
206 | #a #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hlmtl
207 elim (lift_inv_bind2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
208 elim (yle_inv_plus_inj2 … Hlmtl) #_ #Hmlt
209 elim (IHW12 … HLK … HVW1) -IHW12 // #V2 #HV12 #HVW2
210 elim (IHU12 … HTU1) -U1 [4: @drop_skip // |2,5: skip |3: /2 width=1 by yle_succ/ ]
211 >yminus_succ1_inj /3 width=5 by cpy_bind, lift_bind, ex2_intro/
212 | #I #G #L #W1 #W2 #U1 #U2 #lt #mt #_ #_ #IHW12 #IHU12 #K #s #l #m #HLK #X #H #Hlmtl
213 elim (lift_inv_flat2 … H) -H #V1 #T1 #HVW1 #HTU1 #H destruct
214 elim (IHW12 … HLK … HVW1) -W1 //
215 elim (IHU12 … HLK … HTU1) -U1 -HLK /3 width=5 by cpy_flat, lift_flat, ex2_intro/
219 (* Advanced inversion lemmas on relocation ***********************************)
221 lemma cpy_inv_lift1_ge_up: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
222 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
223 l ≤ lt → lt ≤ l + m → l + m ≤ lt + mt →
224 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[l, lt + mt - (l + m)] T2 & ⬆[l, m] T2 ≡ U2.
225 #G #L #U1 #U2 #lt #mt #HU12 #K #s #l #m #HLK #T1 #HTU1 #Hllt #Hltlm #Hlmlmt
226 elim (cpy_split_up … HU12 (l + m)) -HU12 // -Hlmlmt #U #HU1 #HU2
227 lapply (cpy_weak … HU1 l m ? ?) -HU1 // [ >ymax_pre_sn_comm // ] -Hllt -Hltlm #HU1
228 lapply (cpy_inv_lift1_eq … HTU1 … HU1) -HU1 #HU1 destruct
229 elim (cpy_inv_lift1_ge … HU2 … HLK … HTU1) -U -L /2 width=3 by ex2_intro/
232 lemma cpy_inv_lift1_be_up: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
233 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
234 lt ≤ l → lt + mt ≤ l + m →
235 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[lt, l-lt] T2 & ⬆[l, m] T2 ≡ U2.
236 #G #L #U1 #U2 #lt #mt #HU12 #K #s #l #m #HLK #T1 #HTU1 #Hltl #Hlmtlm
237 lapply (cpy_weak … HU12 lt (l+m-lt) ? ?) -HU12 //
238 [ >ymax_pre_sn_comm /2 width=1 by yle_plus_dx1_trans/ ] -Hlmtlm #HU12
239 elim (cpy_inv_lift1_be … HU12 … HLK … HTU1) -U1 -L /2 width=3 by ex2_intro/
242 lemma cpy_inv_lift1_le_up: ∀G,L,U1,U2,lt,mt. ⦃G, L⦄ ⊢ U1 ▶[lt, mt] U2 →
243 ∀K,s,l,m. ⬇[s, l, m] L ≡ K → ∀T1. ⬆[l, m] T1 ≡ U1 →
244 lt ≤ l → l ≤ lt + mt → lt + mt ≤ l + m →
245 ∃∃T2. ⦃G, K⦄ ⊢ T1 ▶[lt, l - lt] T2 & ⬆[l, m] T2 ≡ U2.
246 #G #L #U1 #U2 #lt #mt #HU12 #K #s #l #m #HLK #T1 #HTU1 #Hltl #Hllmt #Hlmtlm
247 elim (cpy_split_up … HU12 l) -HU12 // #U #HU1 #HU2
248 elim (cpy_inv_lift1_le … HU1 … HLK … HTU1) -U1
249 [2: >ymax_pre_sn_comm // ] -Hltl #T #HT1 #HTU
250 lapply (cpy_weak … HU2 l m ? ?) -HU2 //
251 [ >ymax_pre_sn_comm // ] -Hllmt -Hlmtlm #HU2
252 lapply (cpy_inv_lift1_eq … HTU … HU2) -L #H destruct /2 width=3 by ex2_intro/