1 (**************************************************************************)
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 *)
13 (**************************************************************************)
15 include "basic_2/rt_equivalence/cpcs_cprs.ma".
16 include "basic_2/dynamic/cnv_preserve.ma".
17 include "basic_2/dynamic/nta.ma".
19 (* NATIVE TYPE ASSIGNMENT FOR TERMS *****************************************)
21 (* Properties based on preservation *****************************************)
23 lemma cnv_cpms_nta (a) (h) (G) (L):
24 ∀T. ⦃G,L⦄ ⊢ T ![a,h] → ∀U.⦃G,L⦄ ⊢ T ➡*[1,h] U → ⦃G,L⦄ ⊢ T :[a,h] U.
25 /3 width=4 by cnv_cast, cnv_cpms_trans/ qed.
27 lemma cnv_nta_sn (a) (h) (G) (L):
28 ∀T. ⦃G,L⦄ ⊢ T ![a,h] → ∃U. ⦃G,L⦄ ⊢ T :[a,h] U.
30 elim (cnv_fwd_cpm_SO … HT) #U #HTU
31 /4 width=2 by cnv_cpms_nta, cpm_cpms, ex_intro/
34 (* Basic_1: was: ty3_typecheck *)
35 lemma nta_typecheck (a) (h) (G) (L):
36 ∀T,U. ⦃G,L⦄ ⊢ T :[a,h] U → ∃T0. ⦃G,L⦄ ⊢ ⓝU.T :[a,h] T0.
37 /3 width=1 by cnv_cast, cnv_nta_sn/ qed-.
39 (* Basic_1: was: ty3_correct *)
40 (* Basic_2A1: was: ntaa_fwd_correct *)
41 lemma nta_fwd_correct (a) (h) (G) (L):
42 ∀T,U. ⦃G,L⦄ ⊢ T :[a,h] U → ∃T0. ⦃G,L⦄ ⊢ U :[a,h] T0.
43 /3 width=2 by nta_fwd_cnv_dx, cnv_nta_sn/ qed-.
45 lemma nta_pure_cnv (h) (G) (L):
46 ∀T,U. ⦃G,L⦄ ⊢ T :*[h] U →
47 ∀V. ⦃G,L⦄ ⊢ ⓐV.U !*[h] → ⦃G,L⦄ ⊢ ⓐV.T :*[h] ⓐV.U.
48 #h #G #L #T #U #H1 #V #H2
49 elim (cnv_inv_cast … H1) -H1 #X0 #HU #HT #HUX0 #HTX0
50 elim (cnv_inv_appl … H2) #n #p #X1 #X2 #_ #HV #_ #HVX1 #HUX2
51 elim (cnv_cpms_conf … HU … HUX0 … HUX2) -HU -HUX2
52 <minus_O_n <minus_n_O #X #HX0 #H
53 elim (cpms_inv_abst_sn … H) -H #X3 #X4 #HX13 #HX24 #H destruct
54 @(cnv_cast … (ⓐV.X0)) [2:|*: /2 width=1 by cpms_appl_dx/ ]
55 @(cnv_appl … X3) [4: |*: /2 width=7 by cpms_trans, cpms_cprs_trans/ ]
59 (* Inversion lemmas based on preservation ***********************************)
61 lemma nta_inv_ldef_sn (a) (h) (G) (K) (V):
62 ∀X2. ⦃G,K.ⓓV⦄ ⊢ #0 :[a,h] X2 →
63 ∃∃W,U. ⦃G,K⦄ ⊢ V :[a,h] W & ⬆*[1] W ≘ U & ⦃G,K.ⓓV⦄ ⊢ U ⬌*[h] X2 & ⦃G,K.ⓓV⦄ ⊢ X2 ![a,h].
65 elim (cnv_inv_cast … H) -H #X1 #HX2 #H1 #HX21 #H2
66 elim (cnv_inv_zero … H1) -H1 #Z #K #V #HV #H destruct
67 elim (cpms_inv_delta_sn … H2) -H2 *
70 /3 width=5 by cnv_cpms_nta, cpcs_cprs_sn, ex4_2_intro/
74 lemma nta_inv_lref_sn (a) (h) (G) (L):
75 ∀X2,i. ⦃G,L⦄ ⊢ #↑i :[a,h] X2 →
76 ∃∃I,K,T2,U2. ⦃G,K⦄ ⊢ #i :[a,h] T2 & ⬆*[1] T2 ≘ U2 & ⦃G,K.ⓘ{I}⦄ ⊢ U2 ⬌*[h] X2 & ⦃G,K.ⓘ{I}⦄ ⊢ X2 ![a,h] & L = K.ⓘ{I}.
78 elim (cnv_inv_cast … H) -H #X1 #HX2 #H1 #HX21 #H2
79 elim (cnv_inv_lref … H1) -H1 #I #K #Hi #H destruct
80 elim (cpms_inv_lref_sn … H2) -H2 *
83 /3 width=9 by cnv_cpms_nta, cpcs_cprs_sn, ex5_4_intro/
87 lemma nta_inv_lref_sn_drops_cnv (a) (h) (G) (L):
88 ∀X2, i. ⦃G,L⦄ ⊢ #i :[a,h] X2 →
89 ∨∨ ∃∃K,V,W,U. ⬇*[i] L ≘ K.ⓓV & ⦃G,K⦄ ⊢ V :[a,h] W & ⬆*[↑i] W ≘ U & ⦃G,L⦄ ⊢ U ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 ![a,h]
90 | ∃∃K,W,U. ⬇*[i] L ≘ K. ⓛW & ⦃G,K⦄ ⊢ W ![a,h] & ⬆*[↑i] W ≘ U & ⦃G,L⦄ ⊢ U ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 ![a,h].
92 elim (cnv_inv_cast … H) -H #X1 #HX2 #H1 #HX21 #H2
93 elim (cnv_inv_lref_drops … H1) -H1 #I #K #V #HLK #HV
94 elim (cpms_inv_lref1_drops … H2) -H2 *
96 | #Y #X #W #H #HVW #HUX1
97 lapply (drops_mono … H … HLK) -H #H destruct
98 /4 width=8 by cnv_cpms_nta, cpcs_cprs_sn, ex5_4_intro, or_introl/
99 | #n #Y #X #U #H #HVU #HUX1 #H0 destruct
100 lapply (drops_mono … H … HLK) -H #H destruct
101 elim (lifts_total V (𝐔❴↑i❵)) #W #HVW
102 lapply (cpms_lifts_bi … HVU (Ⓣ) … L … HVW … HUX1) -U
103 [ /2 width=2 by drops_isuni_fwd_drop2/ ] #HWX1
104 /4 width=9 by cprs_div, ex5_3_intro, or_intror/
108 lemma nta_inv_bind_sn_cnv (a) (h) (p) (I) (G) (K) (X2):
109 ∀V,T. ⦃G,K⦄ ⊢ ⓑ{p,I}V.T :[a,h] X2 →
110 ∃∃U. ⦃G,K⦄ ⊢ V ![a,h] & ⦃G,K.ⓑ{I}V⦄ ⊢ T :[a,h] U & ⦃G,K⦄ ⊢ ⓑ{p,I}V.U ⬌*[h] X2 & ⦃G,K⦄ ⊢ X2 ![a,h].
111 #a #h #p * #G #K #X2 #V #T #H
112 elim (cnv_inv_cast … H) -H #X1 #HX2 #H1 #HX21 #H2
113 elim (cnv_inv_bind … H1) -H1 #HV #HT
114 [ elim (cpms_inv_abbr_sn_dx … H2) -H2 *
115 [ #V0 #U #HV0 #HTU #H destruct
116 /4 width=5 by cnv_cpms_nta, cprs_div, cpms_bind, ex4_intro/
117 | #U #HTU #HX1U #H destruct
118 /4 width=5 by cnv_cpms_nta, cprs_div, cpms_zeta, ex4_intro/
120 | elim (cpms_inv_abst_sn … H2) -H2 #V0 #U #HV0 #HTU #H destruct
121 /4 width=5 by cnv_cpms_nta, cprs_div, cpms_bind, ex4_intro/
125 (* Basic_1: uses: ty3_gen_appl *)
126 lemma nta_inv_appl_sn (h) (G) (L) (X2):
127 ∀V,T. ⦃G,L⦄ ⊢ ⓐV.T :[h] X2 →
128 ∃∃p,W,U. ⦃G,L⦄ ⊢ V :[h] W & ⦃G,L⦄ ⊢ T :[h] ⓛ{p}W.U & ⦃G,L⦄ ⊢ ⓐV.ⓛ{p}W.U ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 ![h].
129 #h #G #L #X2 #V #T #H
130 elim (cnv_inv_cast … H) -H #X #HX2 #H1 #HX2 #H2
131 elim (cnv_inv_appl … H1) * [ | #n ] #p #W #U #Hn #HV #HT #HVW #HTU
132 [ lapply (cnv_cpms_trans … HT … HTU) #H
133 elim (cnv_inv_bind … H) -H #_ #HU
134 elim (cnv_fwd_cpm_SO … HU) #U0 #HU0 -HU
135 lapply (cpms_step_dx … HTU 1 (ⓛ{p}W.U0) ?) -HTU [ /2 width=1 by cpm_bind/ ] #HTU
136 | lapply (le_n_O_to_eq n ?) [ /3 width=1 by le_S_S_to_le/ ] -Hn #H destruct
138 lapply (cpms_appl_dx … V V … HTU) [1,3: // ] #HVTU
139 elim (cnv_cpms_conf … H1 … H2 … HVTU) -H1 -H2 -HVTU <minus_n_n #X0 #HX0 #HUX0
140 @ex4_3_intro [6,13: |*: /2 width=5 by cnv_cpms_nta/ ]
141 /3 width=5 by cprs_div, cprs_trans/
149 →∀Q_:∀x_3:A.∀x_2:B.∀x_1:B.ltc A __6 B __4 x_3 x_2 x_1→Prop
152 .∀b2:B.∀x_5:__5 a b1 b2.Q_ a b1 b2 (ltc_rc A __8 B __6 a b1 b2 x_5))
158 .∀x_7:ltc A __10 B __8 a1 b1 b
159 .∀x_6:ltc A __11 B __9 a2 b b2
162 →Q_ (__14 a1 a2) b1 b2
163 (ltc_trans A __14 B __12 a1 a2 b1 b b2 x_7 x_6))
165 .∀x_2:B.∀x_1:B.∀x_4:ltc A __9 B __7 x_3 x_2 x_1.Q_ x_3 x_2 x_1 x_4)
167 lemma nta_inv_pure_sn_cnv (h) (G) (L) (X2):
168 ∀V,T. ⦃G,L⦄ ⊢ ⓐV.T :*[h] X2 →
169 ∨∨ ∃∃p,W,T0,U0. ⦃G,L⦄ ⊢ V :*[h] W & ⦃G,L⦄ ⊢ ⓛ{p}W.T0 :*[h] ⓛ{p}W.U0 & ⦃G,L⦄ ⊢ T ➡*[h] ⓛ{p}W.T0 & ⦃G,L⦄ ⊢ ⓐV.ⓛ{p}W.U0 ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 !*[h]
170 | ∃∃U. ⦃G,L⦄ ⊢ T :*[h] U & ⦃G,L⦄ ⊢ ⓐV.U !*[h] & ⦃G,L⦄ ⊢ ⓐV.U ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 !*[h].
171 #h #G #L #X2 #V #T #H
172 elim (cnv_inv_cast … H) -H #X1 #HX2 #H1 #HX21 #H
173 elim (cnv_inv_appl … H1) -H1 * [| #n ] #p #W0 #T0 #_ #HV #HT #HW0 #HT0
174 lapply (cnv_cpms_trans … HT … HT0) #H
175 elim (cnv_inv_bind … H) -H #_ #H1T0
176 [ elim (cpms_inv_appl_sn_decompose … H) -H #U #HTU #HUX1
179 [ #V0 #U0 #HV0 #HU0 #H destruct
180 elim (cnv_cpms_conf … HT … HT0 … HU0)
181 <minus_O_n <minus_n_O #X #H #HU0X
182 elim (cpms_inv_abst_sn … H) -H #W1 #U1 #HW01 #HU01 #H destruct
184 @(ex5_4_intro … U1 … HT0 … HX2) -HX2
185 [ /2 width=1 by cnv_cpms_nta/
186 | @nta_bind_cnv /2 width=4 by cnv_cpms_trans/ /2 width=3 by cnv_cpms_nta/
187 | @(cpcs_cprs_div … HX21) -HX21
188 @(cprs_div … (ⓐV0.ⓛ{p}W1.U1))
189 /3 width=1 by cpms_appl, cpms_appl_dx, cpms_bind/
192 (* Basic_2A1: uses: nta_inv_cast1 *)
193 lemma nta_inv_cast_sn (a) (h) (G) (L) (X2):
194 ∀U,T. ⦃G,L⦄ ⊢ ⓝU.T :[a,h] X2 →
195 ∧∧ ⦃G,L⦄ ⊢ T :[a,h] U & ⦃G,L⦄ ⊢ U ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 ![a,h].
196 #a #h #G #L #X2 #U #T #H
197 elim (cnv_inv_cast … H) -H #X0 #HX2 #H1 #HX20 #H2
198 elim (cnv_inv_cast … H1) #X #HU #HT #HUX #HTX
199 elim (cpms_inv_cast1 … H2) -H2 [ * || * ]
200 [ #U0 #T0 #HU0 #HT0 #H destruct -HU -HU0
201 elim (cnv_cpms_conf … HT … HTX … HT0) -HT -HTX -HT0
202 <minus_n_n #T1 #HXT1 #HT01
203 @and3_intro // @(cprs_div … T1) /3 width=4 by cprs_trans, cpms_eps/ (**) (* full auto too slow *)
205 elim (cnv_cpms_conf … HT … HTX … HTX0) -HT -HTX -HTX0
206 <minus_n_n #T1 #HXT1 #HXT01
207 @and3_intro // @(cprs_div … T1) /2 width=3 by cprs_trans/ (**) (* full auto too slow *)
208 | #m #HUX0 #H destruct -HT -HTX
209 elim (cnv_cpms_conf … HU … HUX … HUX0) -HU -HUX0
210 <minus_n_n #U1 #HXU1 #HXU01
211 @and3_intro // @(cprs_div … U1) /2 width=3 by cprs_trans/ (**) (* full auto too slow *)
215 (* Basic_1: uses: ty3_gen_cast *)
216 lemma nta_inv_cast_sn_old (a) (h) (G) (L) (X2):
217 ∀T0,T1. ⦃G,L⦄ ⊢ ⓝT1.T0 :[a,h] X2 →
218 ∃∃T2. ⦃G,L⦄ ⊢ T0 :[a,h] T1 & ⦃G,L⦄ ⊢ T1 :[a,h] T2 & ⦃G,L⦄ ⊢ ⓝT2.T1 ⬌*[h] X2 & ⦃G,L⦄ ⊢ X2 ![a,h].
219 #a #h #G #L #X2 #T0 #T1 #H
220 elim (cnv_inv_cast … H) -H #X0 #HX2 #H1 #HX20 #H2
221 elim (cnv_inv_cast … H1) #X #HT1 #HT0 #HT1X #HT0X
222 elim (cpms_inv_cast1 … H2) -H2 [ * || * ]
223 [ #U1 #U0 #HTU1 #HTU0 #H destruct
224 elim (cnv_cpms_conf … HT0 … HT0X … HTU0) -HT0 -HT0X -HTU0
225 <minus_n_n #X0 #HX0 #HUX0
226 lapply (cprs_trans … HT1X … HX0) -X #HT1X0
227 /5 width=7 by cnv_cpms_nta, cpcs_cprs_div, cprs_div, cpms_cast, ex4_intro/
229 elim (cnv_cpms_conf … HT0 … HT0X … HTX0) -HT0 -HT0X -HTX0
230 <minus_n_n #X1 #HX1 #HX01
231 elim (cnv_nta_sn … HT1) -HT1 #U1 #HTU1
232 lapply (cprs_trans … HT1X … HX1) -X #HTX1
233 lapply (cprs_trans … HX20 … HX01) -X0 #HX21
234 /4 width=5 by cprs_div, cpms_eps, ex4_intro/
235 | #n #HT1X0 #H destruct -X -HT0
236 elim (cnv_nta_sn … HT1) -HT1 #U1 #HTU1
237 /4 width=5 by cprs_div, cpms_eps, ex4_intro/
241 (* Forward lemmas based on preservation *************************************)
243 (* Basic_1: was: ty3_unique *)
244 theorem nta_mono (a) (h) (G) (L) (T):
245 ∀U1. ⦃G,L⦄ ⊢ T :[a,h] U1 → ∀U2. ⦃G,L⦄ ⊢ T :[a,h] U2 → ⦃G,L⦄ ⊢ U1 ⬌*[h] U2.
246 #a #h #G #L #T #U1 #H1 #U2 #H2
247 elim (cnv_inv_cast … H1) -H1 #X1 #_ #_ #HUX1 #HTX1
248 elim (cnv_inv_cast … H2) -H2 #X2 #_ #HT #HUX2 #HTX2
249 elim (cnv_cpms_conf … HT … HTX1 … HTX2) -T <minus_n_n #X #HX1 #HX2
250 /3 width=5 by cprs_div, cprs_trans/