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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/notation/relations/ineint_5.ma".
16 include "basic_2/grammar/aarity.ma".
17 include "basic_2/multiple/mr2_mr2.ma".
18 include "basic_2/multiple/lifts_lift_vector.ma".
19 include "basic_2/multiple/drops_drop.ma".
20 include "basic_2/computation/gcp.ma".
22 (* GENERIC COMPUTATION PROPERTIES *******************************************)
24 definition S0 ≝ λC:candidate. ∀G,L2,L1,T1,d,e.
25 C G L1 T1 → ∀T2. ⇩[Ⓕ, d, e] L2 ≡ L1 → ⇧[d, e] T1 ≡ T2 → C G L2 T2.
27 definition S0s ≝ λC:candidate.
28 ∀G,L1,L2,des. ⇩*[Ⓕ, des] L2 ≡ L1 →
29 ∀T1,T2. ⇧*[des] T1 ≡ T2 → C G L1 T1 → C G L2 T2.
31 (* Note: this is Girard's CR1 *)
32 definition S1 ≝ λRP,C:candidate.
33 ∀G,L,T. C G L T → RP G L T.
35 (* Note: this is Tait's iii, or Girard's CR4 *)
36 definition S2 ≝ λRR:relation4 genv lenv term term. λRS:relation term. λRP,C:candidate.
37 ∀G,L,Vs. all … (RP G L) Vs →
38 ∀T. 𝐒⦃T⦄ → NF … (RR G L) RS T → C G L (ⒶVs.T).
40 (* Note: this generalizes Tait's ii *)
41 definition S3 ≝ λC:candidate.
43 C G L (ⒶVs.ⓓ{a}ⓝW.V.T) → C G L (ⒶVs.ⓐV.ⓛ{a}W.T).
45 definition S4 ≝ λRP,C:candidate.
46 ∀G,L,Vs. all … (RP G L) Vs → ∀k. C G L (ⒶVs.⋆k).
48 definition S5 ≝ λC:candidate. ∀I,G,L,K,Vs,V1,V2,i.
49 C G L (ⒶVs.V2) → ⇧[0, i+1] V1 ≡ V2 →
50 ⇩[i] L ≡ K.ⓑ{I}V1 → C G L (ⒶVs.#i).
52 definition S6 ≝ λRP,C:candidate.
53 ∀G,L,V1s,V2s. ⇧[0, 1] V1s ≡ V2s →
54 ∀a,V,T. C G (L.ⓓV) (ⒶV2s.T) → RP G L V → C G L (ⒶV1s.ⓓ{a}V.T).
56 definition S7 ≝ λC:candidate.
57 ∀G,L,Vs,T,W. C G L (ⒶVs.T) → C G L (ⒶVs.W) → C G L (ⒶVs.ⓝW.T).
59 (* requirements for the generic reducibility candidate *)
60 record gcr (RR:relation4 genv lenv term term) (RS:relation term) (RP,C:candidate) : Prop ≝
71 (* the functional construction for candidates *)
72 definition cfun: candidate → candidate → candidate ≝
73 λC1,C2,G,K,T. ∀L,V,U,des.
74 ⇩*[Ⓕ, des] L ≡ K → ⇧*[des] T ≡ U → C1 G L V → C2 G L (ⓐV.U).
76 (* the reducibility candidate associated to an atomic arity *)
77 let rec acr (RP:candidate) (A:aarity) on A: candidate ≝
80 | APair B A ⇒ cfun (acr RP B) (acr RP A)
84 "candidate of reducibility of an atomic arity (abstract)"
85 'InEInt RP G L T A = (acr RP A G L T).
87 (* Basic properties *********************************************************)
89 (* Basic_1: was: sc3_lift1 *)
90 lemma gcr_lifts: ∀C. S0 C → S0s C.
91 #C #HC #G #L1 #L2 #des #H elim H -L1 -L2 -des
92 [ #L #T1 #T2 #H #HT1 <(lifts_inv_nil … H) -H //
93 | #L1 #L #L2 #des #d #e #_ #HL2 #IHL #T2 #T1 #H #HLT2
94 elim (lifts_inv_cons … H) -H /3 width=10 by/
98 lemma rp_lifts: ∀RR,RS,RP. gcr RR RS RP RP →
99 ∀des,G,L0,L,V,V0. ⇩*[Ⓕ, des] L0 ≡ L → ⇧*[des] V ≡ V0 →
100 RP G L V → RP G L0 V0.
101 #RR #RS #RP #HRP #des #G #L0 #L #V #V0 #HL0 #HV0 #HV
102 @gcr_lifts /width=7 by/
106 (* Basic_1: was only: sns3_lifts1 *)
107 lemma rp_liftsv_all: ∀RR,RS,RP. gcr RR RS RP RP →
108 ∀des,G,L0,L,Vs,V0s. ⇩*[Ⓕ, des] L0 ≡ L → ⇧*[des] Vs ≡ V0s →
109 all … (RP G L) Vs → all … (RP G L0) V0s.
110 #RR #RS #RP #HRP #des #G #L0 #L #Vs #V0s #HL0 #H elim H -Vs -V0s normalize //
111 #T1s #T2s #T1 #T2 #HT12 #_ #IHT2s * /3 width=7 by rp_lifts, conj/
115 sc3_sn3 sc3_abst sc3_appl sc3_abbr sc3_bind sc3_cast sc3_lift
117 lemma acr_gcr: ∀RR,RS,RP. gcp RR RS RP → gcr RR RS RP RP →
118 ∀A. gcr RR RS RP (acr RP A).
119 #RR #RS #RP #H1RP #H2RP #A elim A -A //
120 #B #A #IHB #IHA @mk_gcr
121 [ /3 width=7 by drops_cons, lifts_cons/
123 elim (cp1 … H1RP G L) #k #HK
124 lapply (H L (⋆k) T (◊) ? ? ?) -H //
125 [ lapply (s2 … IHB G L (◊) … HK) //
126 | #H @(cp2 … H1RP … k) @(s1 … IHA) //
128 | #G #L #Vs #HVs #T #H1T #H2T #L0 #V0 #X #des #HL0 #H #HB
129 elim (lifts_inv_applv1 … H) -H #V0s #T0 #HV0s #HT0 #H destruct
130 lapply (s1 … IHB … HB) #HV0
131 @(s2 … IHA … (V0 @ V0s))
132 /3 width=14 by rp_liftsv_all, gcp_lifts, cp0, lifts_simple_dx, conj/
133 | #a #G #L #Vs #U #T #W #HA #L0 #V0 #X #des #HL0 #H #HB
134 elim (lifts_inv_applv1 … H) -H #V0s #Y #HV0s #HY #H destruct
135 elim (lifts_inv_flat1 … HY) -HY #U0 #X #HU0 #HX #H destruct
136 elim (lifts_inv_bind1 … HX) -HX #W0 #T0 #HW0 #HT0 #H destruct
137 @(s3 … IHA … (V0 @ V0s)) /5 width=6 by lifts_applv, lifts_flat, lifts_bind/
138 | #G #L #Vs #HVs #k #L0 #V0 #X #des #HL0 #H #HB
139 elim (lifts_inv_applv1 … H) -H #V0s #Y #HV0s #HY #H destruct
140 >(lifts_inv_sort1 … HY) -Y
141 lapply (s1 … IHB … HB) #HV0
142 @(s4 … IHA … (V0 @ V0s)) /3 width=7 by rp_liftsv_all, conj/
143 | #I #G #L #K #Vs #V1 #V2 #i #HA #HV12 #HLK #L0 #V0 #X #des #HL0 #H #HB
144 elim (lifts_inv_applv1 … H) -H #V0s #Y #HV0s #HY #H destruct
145 elim (lifts_inv_lref1 … HY) -HY #i0 #Hi0 #H destruct
146 elim (drops_drop_trans … HL0 … HLK) #X #des0 #i1 #HL02 #H #Hi1 #Hdes0
147 >(at_mono … Hi1 … Hi0) in HL02; -i1 #HL02
148 elim (drops_inv_skip2 … Hdes0 … H) -H -des0 #L2 #W1 #des0 #Hdes0 #HLK #HVW1 #H destruct
149 elim (lift_total W1 0 (i0 + 1)) #W2 #HW12
150 elim (lifts_lift_trans … Hdes0 … HVW1 … HW12) // -Hdes0 -Hi0 #V3 #HV13 #HVW2
151 >(lift_mono … HV13 … HV12) in HVW2; -V3 #HVW2
152 @(s5 … IHA … (V0 @ V0s) … HW12 HL02) /3 width=5 by lifts_applv/
153 | #G #L #V1s #V2s #HV12s #a #V #T #HA #HV #L0 #V10 #X #des #HL0 #H #HB
154 elim (lifts_inv_applv1 … H) -H #V10s #Y #HV10s #HY #H destruct
155 elim (lifts_inv_bind1 … HY) -HY #V0 #T0 #HV0 #HT0 #H destruct
156 elim (lift_total V10 0 1) #V20 #HV120
157 elim (liftv_total 0 1 V10s) #V20s #HV120s
158 @(s6 … IHA … (V10 @ V10s) (V20 @ V20s)) /3 width=7 by rp_lifts, liftv_cons/
159 @(HA … (des + 1)) /2 width=2 by drops_skip/
161 elim (liftsv_liftv_trans_le … HV10s … HV120s) -V10s #V10s #HV10s #HV120s
162 >(liftv_mono … HV12s … HV10s) -V1s //
163 | @(s0 … IHB … HB … HV120) /2 width=2 by drop_drop/
165 | #G #L #Vs #T #W #HA #HW #L0 #V0 #X #des #HL0 #H #HB
166 elim (lifts_inv_applv1 … H) -H #V0s #Y #HV0s #HY #H destruct
167 elim (lifts_inv_flat1 … HY) -HY #W0 #T0 #HW0 #HT0 #H destruct
168 @(s7 … IHA … (V0 @ V0s)) /3 width=5 by lifts_applv/
172 lemma acr_abst: ∀RR,RS,RP. gcp RR RS RP → gcr RR RS RP RP →
173 ∀a,G,L,W,T,A,B. ⦃G, L, W⦄ ϵ[RP] 〚B〛 → (
174 ∀L0,V0,W0,T0,des. ⇩*[Ⓕ, des] L0 ≡ L → ⇧*[des] W ≡ W0 → ⇧*[des + 1] T ≡ T0 →
175 ⦃G, L0, V0⦄ ϵ[RP] 〚B〛 → ⦃G, L0, W0⦄ ϵ[RP] 〚B〛 → ⦃G, L0.ⓓⓝW0.V0, T0⦄ ϵ[RP] 〚A〛
177 ⦃G, L, ⓛ{a}W.T⦄ ϵ[RP] 〚②B.A〛.
178 #RR #RS #RP #H1RP #H2RP #a #G #L #W #T #A #B #HW #HA #L0 #V0 #X #des #HL0 #H #HB
179 lapply (acr_gcr … H1RP H2RP A) #HCA
180 lapply (acr_gcr … H1RP H2RP B) #HCB
181 elim (lifts_inv_bind1 … H) -H #W0 #T0 #HW0 #HT0 #H destruct
182 lapply (gcr_lifts … HL0 … HW0 HW) -HW [ @(s0 … HCB) ] #HW0
183 lapply (s3 … HCA … a G L0 (◊)) #H @H -H
184 lapply (s6 … HCA G L0 (◊) (◊) ?) // #H @H -H
186 | lapply (s1 … HCB) -HCB #HCB
187 lapply (s7 … H2RP G L0 (◊)) /3 width=1 by/
191 (* Basic_1: removed theorems 2: sc3_arity_gen sc3_repl *)
192 (* Basic_1: removed local theorems 1: sc3_sn3_abst *)