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 "ground_2/relocation/rtmap_sle.ma".
16 include "ground_2/relocation/rtmap_sdj.ma".
17 include "basic_2/notation/relations/relationstar_5.ma".
18 include "basic_2/syntax/lenv.ma".
20 (* GENERIC ENTRYWISE EXTENSION OF CONTEXT-SENSITIVE REALTIONS FOR TERMS *****)
22 inductive lexs (RN,RP:relation3 lenv bind bind): rtmap → relation lenv ≝
23 | lexs_atom: ∀f. lexs RN RP f (⋆) (⋆)
24 | lexs_next: ∀f,I1,I2,L1,L2.
25 lexs RN RP f L1 L2 → RN L1 I1 I2 →
26 lexs RN RP (⫯f) (L1.ⓘ{I1}) (L2.ⓘ{I2})
27 | lexs_push: ∀f,I1,I2,L1,L2.
28 lexs RN RP f L1 L2 → RP L1 I1 I2 →
29 lexs RN RP (↑f) (L1.ⓘ{I1}) (L2.ⓘ{I2})
32 interpretation "generic entrywise extension (local environment)"
33 'RelationStar RN RP f L1 L2 = (lexs RN RP f L1 L2).
35 definition R_pw_confluent2_lexs: relation3 lenv bind bind → relation3 lenv bind bind →
36 relation3 lenv bind bind → relation3 lenv bind bind →
37 relation3 lenv bind bind → relation3 lenv bind bind →
38 relation3 rtmap lenv bind ≝
39 λR1,R2,RN1,RP1,RN2,RP2,f,L0,T0.
40 ∀T1. R1 L0 T0 T1 → ∀T2. R2 L0 T0 T2 →
41 ∀L1. L0 ⪤*[RN1, RP1, f] L1 → ∀L2. L0 ⪤*[RN2, RP2, f] L2 →
42 ∃∃T. R2 L1 T1 T & R1 L2 T2 T.
44 definition lexs_transitive: relation5 (relation3 lenv bind bind)
45 (relation3 lenv bind bind) … ≝
47 ∀f,L1,T1,T. R1 L1 T1 T → ∀L2. L1 ⪤*[RN, RP, f] L2 →
48 ∀T2. R2 L2 T T2 → R3 L1 T1 T2.
50 (* Basic inversion lemmas ***************************************************)
52 fact lexs_inv_atom1_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → X = ⋆ → Y = ⋆.
53 #RN #RP #f #X #Y * -f -X -Y //
54 #f #I1 #I2 #L1 #L2 #_ #_ #H destruct
57 (* Basic_2A1: includes lpx_sn_inv_atom1 *)
58 lemma lexs_inv_atom1: ∀RN,RP,f,Y. ⋆ ⪤*[RN, RP, f] Y → Y = ⋆.
59 /2 width=6 by lexs_inv_atom1_aux/ qed-.
61 fact lexs_inv_next1_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → ∀g,J1,K1. X = K1.ⓘ{J1} → f = ⫯g →
62 ∃∃J2,K2. K1 ⪤*[RN, RP, g] K2 & RN K1 J1 J2 & Y = K2.ⓘ{J2}.
63 #RN #RP #f #X #Y * -f -X -Y
64 [ #f #g #J1 #K1 #H destruct
65 | #f #I1 #I2 #L1 #L2 #HL #HI #g #J1 #K1 #H1 #H2 <(injective_next … H2) -g destruct
66 /2 width=5 by ex3_2_intro/
67 | #f #I1 #I2 #L1 #L2 #_ #_ #g #J1 #K1 #_ #H elim (discr_push_next … H)
71 (* Basic_2A1: includes lpx_sn_inv_pair1 *)
72 lemma lexs_inv_next1: ∀RN,RP,g,J1,K1,Y. K1.ⓘ{J1} ⪤*[RN, RP, ⫯g] Y →
73 ∃∃J2,K2. K1 ⪤*[RN, RP, g] K2 & RN K1 J1 J2 & Y = K2.ⓘ{J2}.
74 /2 width=7 by lexs_inv_next1_aux/ qed-.
76 fact lexs_inv_push1_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → ∀g,J1,K1. X = K1.ⓘ{J1} → f = ↑g →
77 ∃∃J2,K2. K1 ⪤*[RN, RP, g] K2 & RP K1 J1 J2 & Y = K2.ⓘ{J2}.
78 #RN #RP #f #X #Y * -f -X -Y
79 [ #f #g #J1 #K1 #H destruct
80 | #f #I1 #I2 #L1 #L2 #_ #_ #g #J1 #K1 #_ #H elim (discr_next_push … H)
81 | #f #I1 #I2 #L1 #L2 #HL #HI #g #J1 #K1 #H1 #H2 <(injective_push … H2) -g destruct
82 /2 width=5 by ex3_2_intro/
86 lemma lexs_inv_push1: ∀RN,RP,g,J1,K1,Y. K1.ⓘ{J1} ⪤*[RN, RP, ↑g] Y →
87 ∃∃J2,K2. K1 ⪤*[RN, RP, g] K2 & RP K1 J1 J2 & Y = K2.ⓘ{J2}.
88 /2 width=7 by lexs_inv_push1_aux/ qed-.
90 fact lexs_inv_atom2_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → Y = ⋆ → X = ⋆.
91 #RN #RP #f #X #Y * -f -X -Y //
92 #f #I1 #I2 #L1 #L2 #_ #_ #H destruct
95 (* Basic_2A1: includes lpx_sn_inv_atom2 *)
96 lemma lexs_inv_atom2: ∀RN,RP,f,X. X ⪤*[RN, RP, f] ⋆ → X = ⋆.
97 /2 width=6 by lexs_inv_atom2_aux/ qed-.
99 fact lexs_inv_next2_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → ∀g,J2,K2. Y = K2.ⓘ{J2} → f = ⫯g →
100 ∃∃J1,K1. K1 ⪤*[RN, RP, g] K2 & RN K1 J1 J2 & X = K1.ⓘ{J1}.
101 #RN #RP #f #X #Y * -f -X -Y
102 [ #f #g #J2 #K2 #H destruct
103 | #f #I1 #I2 #L1 #L2 #HL #HI #g #J2 #K2 #H1 #H2 <(injective_next … H2) -g destruct
104 /2 width=5 by ex3_2_intro/
105 | #f #I1 #I2 #L1 #L2 #_ #_ #g #J2 #K2 #_ #H elim (discr_push_next … H)
109 (* Basic_2A1: includes lpx_sn_inv_pair2 *)
110 lemma lexs_inv_next2: ∀RN,RP,g,J2,X,K2. X ⪤*[RN, RP, ⫯g] K2.ⓘ{J2} →
111 ∃∃J1,K1. K1 ⪤*[RN, RP, g] K2 & RN K1 J1 J2 & X = K1.ⓘ{J1}.
112 /2 width=7 by lexs_inv_next2_aux/ qed-.
114 fact lexs_inv_push2_aux: ∀RN,RP,f,X,Y. X ⪤*[RN, RP, f] Y → ∀g,J2,K2. Y = K2.ⓘ{J2} → f = ↑g →
115 ∃∃J1,K1. K1 ⪤*[RN, RP, g] K2 & RP K1 J1 J2 & X = K1.ⓘ{J1}.
116 #RN #RP #f #X #Y * -f -X -Y
117 [ #f #J2 #K2 #g #H destruct
118 | #f #I1 #I2 #L1 #L2 #_ #_ #g #J2 #K2 #_ #H elim (discr_next_push … H)
119 | #f #I1 #I2 #L1 #L2 #HL #HI #g #J2 #K2 #H1 #H2 <(injective_push … H2) -g destruct
120 /2 width=5 by ex3_2_intro/
124 lemma lexs_inv_push2: ∀RN,RP,g,J2,X,K2. X ⪤*[RN, RP, ↑g] K2.ⓘ{J2} →
125 ∃∃J1,K1. K1 ⪤*[RN, RP, g] K2 & RP K1 J1 J2 & X = K1.ⓘ{J1}.
126 /2 width=7 by lexs_inv_push2_aux/ qed-.
128 (* Basic_2A1: includes lpx_sn_inv_pair *)
129 lemma lexs_inv_next: ∀RN,RP,f,I1,I2,L1,L2.
130 L1.ⓘ{I1} ⪤*[RN, RP, ⫯f] L2.ⓘ{I2} →
131 L1 ⪤*[RN, RP, f] L2 ∧ RN L1 I1 I2.
132 #RN #RP #f #I1 #I2 #L1 #L2 #H elim (lexs_inv_next1 … H) -H
133 #I0 #L0 #HL10 #HI10 #H destruct /2 width=1 by conj/
136 lemma lexs_inv_push: ∀RN,RP,f,I1,I2,L1,L2.
137 L1.ⓘ{I1} ⪤*[RN, RP, ↑f] L2.ⓘ{I2} →
138 L1 ⪤*[RN, RP, f] L2 ∧ RP L1 I1 I2.
139 #RN #RP #f #I1 #I2 #L1 #L2 #H elim (lexs_inv_push1 … H) -H
140 #I0 #L0 #HL10 #HI10 #H destruct /2 width=1 by conj/
143 lemma lexs_inv_tl: ∀RN,RP,f,I1,I2,L1,L2. L1 ⪤*[RN, RP, ⫱f] L2 →
144 RN L1 I1 I2 → RP L1 I1 I2 →
145 L1.ⓘ{I1} ⪤*[RN, RP, f] L2.ⓘ{I2}.
146 #RN #RP #f #I1 #I2 #L2 #L2 elim (pn_split f) *
147 /2 width=1 by lexs_next, lexs_push/
150 (* Basic forward lemmas *****************************************************)
152 lemma lexs_fwd_bind: ∀RN,RP,f,I1,I2,L1,L2.
153 L1.ⓘ{I1} ⪤*[RN, RP, f] L2.ⓘ{I2} →
154 L1 ⪤*[RN, RP, ⫱f] L2.
155 #RN #RP #f #I1 #I2 #L1 #L2 #Hf
156 elim (pn_split f) * #g #H destruct
157 [ elim (lexs_inv_push … Hf) | elim (lexs_inv_next … Hf) ] -Hf //
160 (* Basic properties *********************************************************)
162 lemma lexs_eq_repl_back: ∀RN,RP,L1,L2. eq_repl_back … (λf. L1 ⪤*[RN, RP, f] L2).
163 #RN #RP #L1 #L2 #f1 #H elim H -f1 -L1 -L2 //
164 #f1 #I1 #I2 #L1 #L2 #_ #HI #IH #f2 #H
165 [ elim (eq_inv_nx … H) -H /3 width=3 by lexs_next/
166 | elim (eq_inv_px … H) -H /3 width=3 by lexs_push/
170 lemma lexs_eq_repl_fwd: ∀RN,RP,L1,L2. eq_repl_fwd … (λf. L1 ⪤*[RN, RP, f] L2).
171 #RN #RP #L1 #L2 @eq_repl_sym /2 width=3 by lexs_eq_repl_back/ (**) (* full auto fails *)
174 lemma lexs_refl: ∀RN,RP. c_reflexive … RN → c_reflexive … RP →
175 ∀f.reflexive … (lexs RN RP f).
176 #RN #RP #HRN #HRP #f #L generalize in match f; -f elim L -L //
177 #L #I #IH #f elim (pn_split f) *
178 #g #H destruct /2 width=1 by lexs_next, lexs_push/
181 lemma lexs_sym: ∀RN,RP.
182 (∀L1,L2,I1,I2. RN L1 I1 I2 → RN L2 I2 I1) →
183 (∀L1,L2,I1,I2. RP L1 I1 I2 → RP L2 I2 I1) →
184 ∀f. symmetric … (lexs RN RP f).
185 #RN #RP #HRN #HRP #f #L1 #L2 #H elim H -L1 -L2 -f
186 /3 width=2 by lexs_next, lexs_push/
189 lemma lexs_pair_repl: ∀RN,RP,f,I1,I2,L1,L2.
190 L1.ⓘ{I1} ⪤*[RN, RP, f] L2.ⓘ{I2} →
191 ∀J1,J2. RN L1 J1 J2 → RP L1 J1 J2 →
192 L1.ⓘ{J1} ⪤*[RN, RP, f] L2.ⓘ{J2}.
193 /3 width=3 by lexs_inv_tl, lexs_fwd_bind/ qed-.
195 lemma lexs_co: ∀RN1,RP1,RN2,RP2. RN1 ⊆ RN2 → RP1 ⊆ RP2 →
196 ∀f,L1,L2. L1 ⪤*[RN1, RP1, f] L2 → L1 ⪤*[RN2, RP2, f] L2.
197 #RN1 #RP1 #RN2 #RP2 #HRN #HRP #f #L1 #L2 #H elim H -f -L1 -L2
198 /3 width=1 by lexs_atom, lexs_next, lexs_push/
201 lemma lexs_co_isid: ∀RN1,RP1,RN2,RP2. RP1 ⊆ RP2 →
202 ∀f,L1,L2. L1 ⪤*[RN1, RP1, f] L2 → 𝐈⦃f⦄ →
203 L1 ⪤*[RN2, RP2, f] L2.
204 #RN1 #RP1 #RN2 #RP2 #HR #f #L1 #L2 #H elim H -f -L1 -L2 //
205 #f #I1 #I2 #K1 #K2 #_ #HI12 #IH #H
206 [ elim (isid_inv_next … H) -H //
207 | /4 width=3 by lexs_push, isid_inv_push/
211 lemma lexs_sdj: ∀RN,RP. RP ⊆ RN →
212 ∀f1,L1,L2. L1 ⪤*[RN, RP, f1] L2 →
213 ∀f2. f1 ∥ f2 → L1 ⪤*[RP, RN, f2] L2.
214 #RN #RP #HR #f1 #L1 #L2 #H elim H -f1 -L1 -L2 //
215 #f1 #I1 #I2 #L1 #L2 #_ #HI12 #IH #f2 #H12
216 [ elim (sdj_inv_nx … H12) -H12 [2,3: // ]
217 #g2 #H #H2 destruct /3 width=1 by lexs_push/
218 | elim (sdj_inv_px … H12) -H12 [2,4: // ] *
219 #g2 #H #H2 destruct /3 width=1 by lexs_next, lexs_push/
223 lemma sle_lexs_trans: ∀RN,RP. RN ⊆ RP →
224 ∀f2,L1,L2. L1 ⪤*[RN, RP, f2] L2 →
225 ∀f1. f1 ⊆ f2 → L1 ⪤*[RN, RP, f1] L2.
226 #RN #RP #HR #f2 #L1 #L2 #H elim H -f2 -L1 -L2 //
227 #f2 #I1 #I2 #L1 #L2 #_ #HI12 #IH #f1 #H12
228 [ elim (pn_split f1) * ]
229 [ /4 width=5 by lexs_push, sle_inv_pn/
230 | /4 width=5 by lexs_next, sle_inv_nn/
231 | elim (sle_inv_xp … H12) -H12 [2,3: // ]
232 #g1 #H #H1 destruct /3 width=5 by lexs_push/
236 lemma sle_lexs_conf: ∀RN,RP. RP ⊆ RN →
237 ∀f1,L1,L2. L1 ⪤*[RN, RP, f1] L2 →
238 ∀f2. f1 ⊆ f2 → L1 ⪤*[RN, RP, f2] L2.
239 #RN #RP #HR #f1 #L1 #L2 #H elim H -f1 -L1 -L2 //
240 #f1 #I1 #I2 #L1 #L2 #_ #HI12 #IH #f2 #H12
241 [2: elim (pn_split f2) * ]
242 [ /4 width=5 by lexs_push, sle_inv_pp/
243 | /4 width=5 by lexs_next, sle_inv_pn/
244 | elim (sle_inv_nx … H12) -H12 [2,3: // ]
245 #g2 #H #H2 destruct /3 width=5 by lexs_next/
249 lemma lexs_sle_split: ∀R1,R2,RP. c_reflexive … R1 → c_reflexive … R2 →
250 ∀f,L1,L2. L1 ⪤*[R1, RP, f] L2 → ∀g. f ⊆ g →
251 ∃∃L. L1 ⪤*[R1, RP, g] L & L ⪤*[R2, cfull, f] L2.
252 #R1 #R2 #RP #HR1 #HR2 #f #L1 #L2 #H elim H -f -L1 -L2
253 [ /2 width=3 by lexs_atom, ex2_intro/ ]
254 #f #I1 #I2 #L1 #L2 #_ #HI12 #IH #y #H
255 [ elim (sle_inv_nx … H ??) -H [ |*: // ] #g #Hfg #H destruct
256 elim (IH … Hfg) -IH -Hfg /3 width=5 by lexs_next, ex2_intro/
257 | elim (sle_inv_px … H ??) -H [1,3: * |*: // ] #g #Hfg #H destruct
258 elim (IH … Hfg) -IH -Hfg /3 width=5 by lexs_next, lexs_push, ex2_intro/
262 lemma lexs_sdj_split: ∀R1,R2,RP. c_reflexive … R1 → c_reflexive … R2 →
263 ∀f,L1,L2. L1 ⪤*[R1, RP, f] L2 → ∀g. f ∥ g →
264 ∃∃L. L1 ⪤*[RP, R1, g] L & L ⪤*[R2, cfull, f] L2.
265 #R1 #R2 #RP #HR1 #HR2 #f #L1 #L2 #H elim H -f -L1 -L2
266 [ /2 width=3 by lexs_atom, ex2_intro/ ]
267 #f #I1 #I2 #L1 #L2 #_ #HI12 #IH #y #H
268 [ elim (sdj_inv_nx … H ??) -H [ |*: // ] #g #Hfg #H destruct
269 elim (IH … Hfg) -IH -Hfg /3 width=5 by lexs_next, lexs_push, ex2_intro/
270 | elim (sdj_inv_px … H ??) -H [1,3: * |*: // ] #g #Hfg #H destruct
271 elim (IH … Hfg) -IH -Hfg /3 width=5 by lexs_next, lexs_push, ex2_intro/
275 lemma lexs_dec: ∀RN,RP.
276 (∀L,I1,I2. Decidable (RN L I1 I2)) →
277 (∀L,I1,I2. Decidable (RP L I1 I2)) →
278 ∀L1,L2,f. Decidable (L1 ⪤*[RN, RP, f] L2).
279 #RN #RP #HRN #HRP #L1 elim L1 -L1 [ * | #L1 #I1 #IH * ]
280 [ /2 width=1 by lexs_atom, or_introl/
281 | #L2 #I2 #f @or_intror #H
282 lapply (lexs_inv_atom1 … H) -H #H destruct
284 lapply (lexs_inv_atom2 … H) -H #H destruct
285 | #L2 #I2 #f elim (IH L2 (⫱f)) -IH #HL12
286 [2: /4 width=3 by lexs_fwd_bind, or_intror/ ]
287 elim (pn_split f) * #g #H destruct
288 [ elim (HRP L1 I1 I2) | elim (HRN L1 I1 I2) ] -HRP -HRN #HV12
289 [1,3: /3 width=1 by lexs_push, lexs_next, or_introl/ ]
291 [ elim (lexs_inv_push … H) | elim (lexs_inv_next … H) ] -H