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.
8 \ / This file is distributed under the terms of the
9 \ / GNU General Public License Version 2
10 V_____________________________________________________________*)
17 include "turing/universal/copy.ma".
23 if is_true(current) (* current state is final *)
35 if is_marked(current) = false (* match ok *)
48 case bit false: move_tape_l
49 case bit true: move_tape_r
50 case null: adv_to_grid_l; move_l; adv_to_grid_l;
57 definition init_match ≝
59 (seq ? (adv_to_mark_r ? (λc:STape.is_grid (\fst c)))
63 (adv_to_mark_l ? (is_marked ?)))))).
65 definition R_init_match ≝ λt1,t2.
66 ∀ls,l,rs,c,d. no_grids (〈c,false〉::l) → no_marks l →
67 t1 = midtape STape ls 〈c,false〉 (l@〈grid,false〉::〈d,false〉::rs) →
68 t2 = midtape STape ls 〈c,true〉 (l@〈grid,false〉::〈d,true〉::rs).
70 lemma sem_init_match : Realize ? init_match R_init_match.
72 cases (sem_seq ????? (sem_mark ?)
73 (sem_seq ????? (sem_adv_to_mark_r ? (λc:STape.is_grid (\fst c)))
74 (sem_seq ????? (sem_move_r ?)
75 (sem_seq ????? (sem_mark ?)
76 (sem_seq ????? (sem_move_l ?)
77 (sem_adv_to_mark_l ? (is_marked ?)))))) intape)
78 #k * #outc * #Hloop #HR
79 @(ex_intro ?? k) @(ex_intro ?? outc) % [@Hloop] -Hloop
80 #ls #l #rs #c #d #Hnogrids #Hnomarks #Hintape
82 #ta * whd in ⊢ (%→?); #Hta lapply (Hta … Hintape) -Hta -Hintape #Hta
83 * #tb * whd in ⊢ (%→?); #Htb cases (Htb … Hta) -Htb -Hta
84 [* #Hgridc @False_ind @(absurd … Hgridc) @eqnot_to_noteq
85 @(Hnogrids 〈c,false〉) @memb_hd ]
86 * #Hgrdic #Htb lapply (Htb l 〈grid,false〉 (〈d,false〉::rs) (refl …) (refl …) ?)
87 [#x #membl @Hnogrids @memb_cons @membl] -Htb #Htb
88 * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb #Htc
89 * #td * whd in ⊢ (%→?); #Htd lapply (Htd … Htc) -Htd -Htc #Htd
90 * #te * whd in ⊢ (%→?); #Hte lapply (Hte … Htd) -Hte -Htd #Hte
91 whd in ⊢ (%→?); #Htf cases (Htf … Hte) -Htf -Hte
92 [* whd in ⊢ ((??%?)→?); #Habs destruct (Habs)]
93 * #_ #Htf lapply (Htf (reverse ? l) 〈c,true〉 ls (refl …) (refl …) ?)
94 [#x #membl @Hnomarks @daemon] -Htf #Htf >Htf >reverse_reverse %
100 init_current_on_match; (* no marks in current *)
107 definition init_copy ≝
108 seq ? init_current_on_match
110 (seq ? (adv_to_mark_r ? (is_marked ?))
113 definition R_init_copy ≝ λt1,t2.
115 no_marks l1 → no_grids l1 →
116 no_marks l2 → is_grid c = false →
117 t1 = midtape STape (l1@〈c,false〉::〈grid,false〉::ls) 〈grid,false〉 (l2@〈comma,true〉::〈d,false〉::rs) →
118 t2 = midtape STape (〈comma,false〉::(reverse ? l2)@〈grid,false〉::l1@〈c,true〉::〈grid,false〉::ls) 〈d,true〉 rs.
120 lemma list_last: ∀A.∀l:list A.
121 l = [ ] ∨ ∃a,l1. l = l1@[a].
122 #A #l <(reverse_reverse ? l) cases (reverse A l)
124 |#a #l1 %2 @(ex_intro ?? a) @(ex_intro ?? (reverse ? l1)) //
128 lemma sem_init_copy : Realize ? init_copy R_init_copy.
130 cases (sem_seq ????? sem_init_current_on_match
131 (sem_seq ????? (sem_move_r ?)
132 (sem_seq ????? (sem_adv_to_mark_r ? (is_marked ?))
133 (sem_adv_mark_r ?))) intape)
134 #k * #outc * #Hloop #HR
135 @(ex_intro ?? k) @(ex_intro ?? outc) % [@Hloop] -Hloop
136 #l1 #l2 #c #ls #d #rs #Hl1marks #Hl1grids #Hl2marks #Hc #Hintape
138 #ta * whd in ⊢ (%→?); #Hta lapply (Hta … Hl1grids Hc Hintape) -Hta -Hintape #Hta
139 * #tb * whd in ⊢ (%→?); #Htb lapply (Htb … Hta) -Htb -Hta
140 generalize in match Hl1marks; -Hl1marks cases (list_last ? l1)
141 [#eql1 >eql1 #Hl1marks whd in ⊢ ((???%)→?); whd in ⊢ ((???(????%))→?); #Htb
142 * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb *
143 [* whd in ⊢ ((??%?)→?); #Htemp destruct (Htemp)]
144 * #_ #Htc lapply (Htc … (refl …) (refl …) ?)
145 [#x #membx @Hl2marks @membx]
146 #Htc whd in ⊢ (%→?); #Houtc lapply (Houtc … Htc) -Houtc -Htc #Houtc
148 |* #c1 * #tl #eql1 >eql1 #Hl1marks >reverse_append >reverse_single
149 whd in ⊢ ((???%)→?); whd in ⊢ ((???(????%))→?);
150 >associative_append whd in ⊢ ((???(????%))→?); #Htb
151 * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb *
152 [* >Hl1marks [#Htemp destruct (Htemp)] @memb_append_l2 @memb_hd]
153 * #_ >append_cons <associative_append #Htc lapply (Htc … (refl …) (refl …) ?)
154 [#x #membx cases (memb_append … membx) -membx #membx
155 [cases (memb_append … membx) -membx #membx
156 [@Hl1marks @memb_append_l1 @daemon
157 |>(memb_single … membx) %
161 #Htc whd in ⊢ (%→?); #Houtc lapply (Houtc … Htc) -Houtc -Htc #Houtc
162 >Houtc >reverse_append >reverse_append >reverse_single
163 >reverse_reverse >associative_append >associative_append
164 >associative_append %
168 definition init_copy ≝
170 (seq ? init_current_on_match
172 (adv_to_mark_r ? (is_marked ?)))).
174 definition R_init_copy ≝ λt1,t2.
176 no_marks l1 → no_grids l1 →
177 no_marks l2 → no_grids l2 → is_grid c = false → is_grid d =false →
178 t1 = midtape STape (l1@〈grid,false〉::l2@〈c,false〉::〈grid,false〉::l3) 〈comma,true〉 (〈d,false〉::rs) →
179 t2 = midtape STape (〈comma,false〉::l1@〈grid,false〉::l2@〈c,true〉::〈grid,false〉::l3) 〈d,true〉 rs.
181 lemma list_last: ∀A.∀l:list A.
182 l = [ ] ∨ ∃a,l1. l = l1@[a].
183 #A #l <(reverse_reverse ? l) cases (reverse A l)
185 |#a #l1 %2 @(ex_intro ?? a) @(ex_intro ?? (reverse ? l1)) //
189 lemma sem_init_copy : Realize ? init_copy R_init_copy.
191 cases (sem_seq ????? (sem_adv_mark_r ?)
192 (sem_seq ????? sem_init_current_on_match
193 (sem_seq ????? (sem_move_r ?)
194 (sem_adv_to_mark_r ? (is_marked ?)))) intape)
195 #k * #outc * #Hloop #HR
196 @(ex_intro ?? k) @(ex_intro ?? outc) % [@Hloop] -Hloop
197 #l1 #l2 #c #l3 #d #rs #Hl1marks #Hl1grids #Hl2marks #Hl2grids #Hc #Hd #Hintape
199 #ta * whd in ⊢ (%→?); #Hta lapply (Hta … Hintape) -Hta -Hintape #Hta
200 * #tb * whd in ⊢ (%→?);
201 >append_cons #Htb lapply (Htb (〈comma,false〉::l1) l2 c … Hta)
203 |#x #membx cases (orb_true_l … membx) -membx #membx
204 [>(\P membx) // | @Hl1grids @membx]
206 * #tc * whd in ⊢ (%→?); #Htc lapply (Htc … Htb) -Htc -Htb
207 >reverse_append >reverse_cons cases (list_last ? l2)
208 [#Hl2 >Hl2 >associative_append whd in ⊢ ((???(??%%%))→?); #Htc
209 whd in ⊢ (%→?); #Htd cases (Htd … Htc) -Htd -Htc
210 [* whd in ⊢ ((??%?)→?); #Habs destruct (Habs)]
211 * #_ #Htf lapply (Htf … (refl …) (refl …) ?)
212 [#x >reverse_cons #membx cases (memb_append … membx) -membx #membx
213 [@Hl1marks @daemon |>(memb_single … membx) //]
215 |#Htf >Htf >reverse_reverse >associative_append %
217 |* #a * #l21 #Heq >Heq >reverse_append >reverse_single
218 >associative_append >associative_append >associative_append whd in ⊢ ((???(??%%%))→?); #Htc
219 whd in ⊢ (%→?); #Htd cases (Htd … Htc) -Htd -Htc
220 [* >Hl2marks [#Habs destruct (Habs) |>Heq @memb_append_l2 @memb_hd]]
221 * #_ <associative_append <associative_append #Htf lapply (Htf … (refl …) (refl …) ?)
222 [#x >reverse_cons #membx cases (memb_append … membx) -membx #membx
223 [cases (memb_append … membx) -membx #membx
224 [@Hl2marks >Heq @memb_append_l1 @daemon
225 |>(memb_single … membx) //]
226 |cases (memb_append … membx) -membx #membx
227 [@Hl1marks @daemon |>(memb_single … membx) //]
229 | #Htf >Htf >reverse_append >reverse_reverse
230 >reverse_append >reverse_reverse >associative_append
231 >reverse_single >associative_append >associative_append
232 >associative_append %
237 include "turing/universal/move_tape.ma".
239 definition exec_move ≝
240 seq ? (adv_to_mark_r … (is_marked ?))
244 (seq ? move_tape (move_r …))))).
246 definition lift_tape ≝ λls,c,rs.
248 let c' ≝ match c0 with
252 mk_tape STape ls c' rs.
254 definition sim_current_of_tape ≝ λt.
255 match current STape t with
256 [ None ⇒ 〈null,false〉
260 t1 = ls # cs c # table # rs
262 let simt ≝ lift_tape ls c rs in
263 let simt' ≝ move_left simt' in
265 t2 = left simt'# cs (sim_current_of_tape simt') # table # right simt'
271 definition R_exec_move ≝ λt1,t2.
272 ∀ls,current,table1,newcurrent,table2,rs.
273 t1 = midtape STape (current@〈grid,false〉::ls) 〈grid,false〉
274 (table1@〈comma,true〉::newcurrent@〈comma,false〉::move::table2@
276 table_TM (table1@〈comma,false〉::newcurrent@〈comma,false〉::move::table2) →
284 if is_true(current) (* current state is final *)
289 if is_marked(current) = false (* match ok *)
295 definition mk_tuple ≝ λc,newc,mv.
296 c @ 〈comma,false〉:: newc @ 〈comma,false〉 :: [〈mv,false〉].
298 inductive match_in_table (c,newc:list STape) (mv:unialpha) : list STape → Prop ≝
301 match_in_table c newc mv (mk_tuple c newc mv@〈bar,false〉::tb)
304 match_in_table c newc mv tb →
305 match_in_table c newc mv (mk_tuple c0 newc0 mv0@〈bar,false〉::tb).
307 definition move_of_unialpha ≝
309 [ bit x ⇒ match x with [ true ⇒ R | false ⇒ L ]
312 definition R_uni_step ≝ λt1,t2.
313 ∀n,table,c,c1,ls,rs,curs,curc,news,newc,mv.
315 match_in_table (〈c,false〉::curs@[〈curc,false〉])
316 (〈c1,false〉::news@[〈newc,false〉]) mv table →
317 t1 = midtape STape (〈grid,false〉::ls) 〈c,false〉
318 (curs@〈curc,false〉::〈grid,false〉::table@〈grid,false〉::rs) →
319 ∀t1',ls1,rs1.t1' = lift_tape ls 〈curc,false〉 rs →
320 (t2 = midtape STape (〈grid,false〉::ls1) 〈c1,false〉
321 (news@〈newc,false〉::〈grid,false〉::table@〈grid,false〉::rs1) ∧
322 lift_tape ls1 〈newc,false〉 rs1 =
323 tape_move STape t1' (Some ? 〈〈newc,false〉,move_of_unialpha mv〉)).
325 definition no_nulls ≝
326 λl:list STape.∀x.memb ? x l = true → is_null (\fst x) = false.
328 definition R_move_tape_r_abstract ≝ λt1,t2.
329 ∀rs,n,table,curc,curconfig,ls.
330 bit_or_null curc = true → only_bits_or_nulls curconfig → table_TM n table →
331 t1 = midtape STape (table@〈grid,false〉::〈curc,false〉::curconfig@〈grid,false〉::ls)
334 ∀t1'.t1' = lift_tape ls 〈curc,false〉 rs →
336 (t2 = midtape STape ls1 〈grid,false〉 (reverse ? curconfig@newc::
337 〈grid,false〉::reverse ? table@〈grid,false〉::rs1) ∧
338 lift_tape ls1 newc rs1 =
339 tape_move_right STape ls 〈curc,false〉 rs).
341 lemma lift_tape_not_null :
342 ∀ls,c,rs. is_null (\fst c) = false →
343 lift_tape ls c rs = mk_tape STape ls (Some ? c) rs.
344 #ls * #c0 #bc0 #rs cases c0
345 [|normalize in ⊢ (%→?); #Hfalse destruct (Hfalse) ]
349 lemma mtr_concrete_to_abstract :
350 ∀t1,t2.R_move_tape_r t1 t2 → R_move_tape_r_abstract t1 t2.
351 #t1 #t2 whd in ⊢(%→?); #Hconcrete
352 #rs #n #table #curc #curconfig #ls #Hcurc #Hcurconfig #Htable #Ht1
353 #Hrsnonulls #t1' #Ht1'
354 cases (Hconcrete … Htable Ht1) //
356 @(ex_intro ?? (〈curc,false〉::ls)) @(ex_intro ?? [])
357 @(ex_intro ?? 〈null,false〉) %
360 | * #r0 * #rs0 * #Hrs #Ht2
361 @(ex_intro ?? (〈curc,false〉::ls)) @(ex_intro ?? rs0)
364 | >Hrs >lift_tape_not_null
366 | @Hrsnonulls >Hrs @memb_hd ] ]