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 "turing/mono.ma".
19 - return its nth element
20 - return the index of a given element
22 axiom FS_crd : FinSet → nat.
23 axiom FS_nth : ∀F:FinSet.nat → option F.
24 axiom index_of_FS : ∀F:FinSet.F → nat.
26 (* unary bit representation (with a given length) of a certain number *)
27 axiom unary_of_nat : nat → nat → (list bool).
29 axiom FinVector : Type[0] → nat → FinSet.
31 definition binary_base_states ≝ initN 6.
33 definition bin0 : binary_base_states ≝ mk_Sig ?? 0 (leb_true_to_le 1 6 (refl …)).
34 definition bin1 : binary_base_states ≝ mk_Sig ?? 1 (leb_true_to_le 2 6 (refl …)).
35 definition bin2 : binary_base_states ≝ mk_Sig ?? 2 (leb_true_to_le 3 6 (refl …)).
36 definition bin3 : binary_base_states ≝ mk_Sig ?? 3 (leb_true_to_le 4 6 (refl …)).
37 definition bin4 : binary_base_states ≝ mk_Sig ?? 4 (leb_true_to_le 5 6 (refl …)).
38 definition bin5 : binary_base_states ≝ mk_Sig ?? 5 (leb_true_to_le 6 6 (refl …)).
40 definition states_binaryTM : FinSet → FinSet → FinSet ≝ λsig,states.
41 FinProd (FinProd states binary_base_states)
42 (FinProd (FinOption sig) (initN (S (S (2 * (FS_crd sig)))))).
44 axiom daemon : ∀T:Type[0].T.
46 definition to_initN : ∀n,m.n < m → initN m ≝ λn,m,Hn.mk_Sig … n ….// qed.
48 definition initN_pred : ∀n.∀m:initN n.initN n ≝ λn,m.mk_Sig … (pred (pi1 … m)) ….
49 cases m #m0 /2 by le_to_lt_to_lt/ qed.
51 definition displ_of_move ≝ λsig,mv.
53 [ L ⇒ S (2*FS_crd sig)
57 lemma le_displ_of_move : ∀sig,mv.displ_of_move sig mv ≤ S (2*FS_crd sig).
61 (* controllare i contatori, molti andranno incrementati di uno *)
62 definition trans_binaryTM : ∀sig,states:FinSet.
63 (states × (option sig) → states × (option sig) × move) →
64 ((states_binaryTM sig states) × (option bool) →
65 (states_binaryTM sig states) × (option bool) × move)
66 ≝ λsig,states,trans,p.
68 let 〈s0,phase,ch,count〉 ≝ s in
69 let (H1 : O < S (S (2*FS_crd sig))) ≝ ? in
70 let (H2 : FS_crd sig < S (S (2*FS_crd sig))) ≝ ? in
71 match pi1 … phase with
72 [ O ⇒ (*** PHASE 0: read ***)
73 match pi1 … count with
74 [ O ⇒ 〈〈s0,bin1,ch,to_initN (FS_crd sig) ? H2〉,None ?,N〉
76 [ Some a0 ⇒ if (a0 == true)
77 then 〈〈s0,bin0,FS_nth sig k,initN_pred … count〉, None ?,R〉
78 else 〈〈s0,bin0,ch,initN_pred … count〉,None ?,R〉
79 | None ⇒ (* Overflow position! *)
80 let 〈s',a',mv〉 ≝ trans 〈s0,None ?〉 in
82 [ None ⇒ (* we don't write anything: go to end of 2 *) 〈〈s0,bin2,None ?,to_initN 0 ? H1〉,None ?,N〉
83 | Some _ ⇒ (* maybe extend tape *) 〈〈s0,bin4,None ?,to_initN O ? H1〉,None ?,R〉 ] ] ]
84 | S phase ⇒ match phase with
85 [ O ⇒ (*** PHASE 1: restart ***)
86 match pi1 … count with
87 [ O ⇒ 〈〈s0,bin2,ch,to_initN (FS_crd sig) ? H2〉,None ?,N〉
88 | S k ⇒ 〈〈s0,bin1,ch,initN_pred … count〉,None ?,L〉 ]
89 | S phase ⇒ match phase with
90 [ O ⇒ (*** PHASE 2: write ***)
91 let 〈s',a',mv〉 ≝ trans 〈s0,ch〉 in
92 match pi1 … count with
93 [ O ⇒ 〈〈s',bin3,ch,to_initN (displ_of_move sig mv) ??〉,None ?,N〉
95 [ None ⇒ 〈〈s0,bin2,ch,initN_pred … count〉,None ?,R〉
96 | Some a0' ⇒ let out ≝ (FS_nth ? k == a') in
97 〈〈s0,bin2,ch,initN_pred … count〉,Some ? out,R〉 ]
99 | S phase ⇒ match phase with
100 [ O ⇒ (*** PHASE 3: move head left ***)
101 match pi1 … count with
102 [ O ⇒ 〈〈s0,bin0,None ?,to_initN (FS_crd sig) ? H2〉, None ?,N〉 (* the end: restart *)
103 | S k ⇒ 〈〈s0,bin3,ch,initN_pred … count〉, None ?,L〉 ]
104 | S phase ⇒ match phase with
105 [ O ⇒ (*** PHASE 4: check position ***)
107 [ None ⇒ (* niltape/rightof: we can write *) 〈〈s0,bin2,ch,to_initN (FS_crd sig) ? H2〉,None ?,N〉
108 | Some _ ⇒ (* leftof *)
109 let 〈s',a',mv〉 ≝ trans 〈s0,ch〉 in
111 [ None ⇒ (* (vacuous) go to end of 2 *) 〈〈s0,bin2,ch,to_initN 0 ? H1〉,None ?,N〉
112 | Some _ ⇒ (* extend tape *) 〈〈s0,bin5,ch,to_initN (FS_crd sig) ? H2〉,None ?,L〉 ]
114 | S _ ⇒ (*** PHASE 5: left extension ***)
115 match pi1 … count with
116 [ O ⇒ 〈〈s0,bin2,ch,to_initN (FS_crd sig) ? H2〉,None ?,R〉
117 | S k ⇒ 〈〈s0,bin5,ch,initN_pred … count〉,Some ? false,L〉 ]]]]]].
118 [2,3: /2 by lt_S_to_lt/] /2 by le_S_S/
121 definition halt_binaryTM : ∀sig,M.states_binaryTM sig (states sig M) → bool ≝
122 λsig,M,s.let 〈s0,phase,ch,count〉 ≝ s in
123 pi1 … phase == O ∧ halt sig M s0.
126 * Una mk_binaryTM prende in input una macchina M e produce una macchina che:
127 * - ha per alfabeto FinBool
128 * - ha stati di tipo ((states … M) × (initN 7)) ×
129 ((option sig) × (initN (2*dimensione dell'alfabeto di M + 1))
130 * dove il primo elemento corrisponde allo stato della macchina input,
131 * il secondo identifica la fase (lettura, scrittura, spostamento)
132 * il terzo identifica il carattere oggetto letto
133 * il quarto è un contatore
134 * - la funzione di transizione viene prodotta da trans_binaryTM
135 * - la funzione di arresto viene prodotta da halt_binaryTM
137 definition mk_binaryTM ≝
139 mk_TM FinBool (states_binaryTM sig (states sig M))
140 (trans_binaryTM sig (states sig M) (trans sig M))
141 (〈start sig M,bin0,None ?,FS_crd sig〉) (halt_binaryTM sig M).
142 /2 by lt_S_to_lt/ qed.
144 definition bin_char ≝ λsig,ch.unary_of_nat (FS_crd sig) (index_of_FS sig ch).
146 definition bin_current ≝ λsig,t.match current ? t with
147 [ None ⇒ [ ] | Some c ⇒ bin_char sig c ].
149 definition tape_bin_lift ≝ λsig,t.
150 let ls' ≝ flatten ? (map ?? (bin_char sig) (left ? t)) in
151 let c' ≝ option_hd ? (bin_current sig t) in
152 let rs' ≝ tail ? (bin_current sig t)@flatten ? (map ?? (bin_char sig) (right ? t)) in
153 mk_tape ? ls' c' rs'.
155 definition R_bin_lift ≝ λsig,R,t1,t2.
156 ∃u1.t1 = tape_bin_lift sig u1 →
157 ∃u2.t2 = tape_bin_lift sig u2 ∧ R u1 u2.
159 definition state_bin_lift :
160 ∀sig.∀M:TM sig.states sig M → states ? (mk_binaryTM ? M)
161 ≝ λsig,M,q.〈q,bin0,None ?,FS_crd sig〉./2 by lt_S_to_lt/ qed.
163 lemma lift_halt_binaryTM :
164 ∀sig,M,q.halt sig M q = halt ? (mk_binaryTM sig M) (state_bin_lift ? M q).
167 lemma binaryTM_bin0_bin1 :
169 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin0,ch,O〉) t)
170 = mk_config ?? (〈q,bin1,ch,to_initN (FS_crd sig) ??〉) t. //
173 lemma binaryTM_bin0_bin2 :
174 ∀sig,M,t,q,ch,k,qn,mv.
175 current ? t = None ? → S k <S (2*FS_crd sig) →
176 〈qn,None ?,mv〉 = trans sig M 〈q,None ?〉 →
177 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin0,ch,S k〉) t)
178 = mk_config ?? (〈q,bin2,None ?,to_initN O ??〉) t. [2,3:/2 by transitive_lt/]
179 #sig #M #t #q #ch #k #qn #mv #Hcur #Hk #Htrans
180 whd in match (step ???); whd in match (trans ???);
184 lemma binaryTM_bin0_bin4 :
185 ∀sig,M,t,q,ch,k,qn,chn,mv.
186 current ? t = None ? → S k <S (2*FS_crd sig) →
187 〈qn,Some ? chn,mv〉 = trans sig M 〈q,None ?〉 →
188 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin0,ch,S k〉) t)
189 = mk_config ?? (〈q,bin4,None ?,to_initN 0 ??〉) (tape_move ? t R). [2,3:/2 by transitive_lt/]
190 #sig #M #t #q #ch #k #qn #chn #mv #Hcur #Hk #Htrans
191 whd in match (step ???); whd in match (trans ???);
195 lemma binaryTM_bin0_true :
197 current ? t = Some ? true → S k <S (2*FS_crd sig) →
198 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin0,ch,S k〉) t)
199 = mk_config ?? (〈q,bin0,FS_nth sig k,to_initN k ??〉) (tape_move ? t R).[2,3:@le_S /2 by lt_S_to_lt/]
200 #sig #M #t #q #ch #k #Hcur #Hk
201 whd in match (step ???); whd in match (trans ???);
205 lemma binaryTM_bin0_false :
207 current ? t = Some ? false → S k <S (2*FS_crd sig) →
208 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin0,ch,S k〉) t)
209 = mk_config ?? (〈q,bin0,ch,to_initN k ??〉) (tape_move ? t R).[2,3:@le_S /2 by lt_S_to_lt/]
210 #sig #M #t #q #ch #k #Hcur #Hk
211 whd in match (step ???); whd in match (trans ???);
216 axiom binary_to_bin_char :∀sig,csl,csr,a.
217 csl@true::csr=bin_char sig a → FS_nth ? (length ? csr) = Some ? a.
219 lemma binaryTM_phase0_midtape_aux :
222 ∀csr,csl,t,ch.length ? csr < S (2*FS_crd sig) →
223 t = mk_tape ? (reverse ? csl@ls) (option_hd ? (csr@rs)) (tail ? (csr@rs)) →
224 csl@csr = bin_char sig a →
225 |csl@csr| = FS_crd sig →
226 (index_of_FS ? a < |csl| → ch = Some ? a) →
227 loopM ? (mk_binaryTM sig M) (S (length ? csr) + k)
228 (mk_config ?? (〈q,bin0,ch,length ? csr〉) t)
229 = loopM ? (mk_binaryTM sig M) k
230 (mk_config ?? (〈q,bin1,Some ? a,FS_crd sig〉)
231 (mk_tape ? (reverse ? (bin_char ? a)@ls) (option_hd ? rs) (tail ? rs))). [2,3:@le_S /2 by O/]
232 #sig #M #q #ls #a #rs #k #Hhalt #csr elim csr
233 [ #csl #t #ch #Hlen #Ht >append_nil #Hcsl #Hlencsl #Hch >loopM_unfold >loop_S_false [|normalize //]
234 >Hch [| >Hlencsl (* lemmatize *) @daemon]
235 <loopM_unfold @eq_f >binaryTM_bin0_bin1 @eq_f >Ht
236 whd in match (step ???); whd in match (trans ???); <Hcsl %
238 [ #csr0 #IH #csl #t #ch #Hlen #Ht #Heq #Hcrd #Hch >loopM_unfold >loop_S_false [|normalize //]
239 <loopM_unfold lapply (binary_to_bin_char … Heq) #Ha >binaryTM_bin0_true
241 lapply (IH (csl@[true]) (tape_move FinBool t R) ??????)
243 | >associative_append @Hcrd
244 | >associative_append @Heq
245 | >Ht whd in match (option_hd ??) in ⊢ (??%?); whd in match (tail ??) in ⊢ (??%?);
248 [ normalize >rev_append_def >rev_append_def >reverse_append %
249 | #r1 #rs1 normalize >rev_append_def >rev_append_def >reverse_append % ]
250 | #c1 #csr1 normalize >rev_append_def >rev_append_def >reverse_append % ]
253 #H whd in match (plus ??); >H @eq_f @eq_f2 %
254 | #csr0 #IH #csl #t #ch #Hlen #Ht #Heq #Hcrd #Hch >loopM_unfold >loop_S_false [|normalize //]
255 <loopM_unfold >binaryTM_bin0_false [| >Ht % ]
256 lapply (IH (csl@[false]) (tape_move FinBool t R) ??????)
258 | (* by cases: if index < |csl|, then Hch, else False *)
260 | >associative_append @Hcrd
261 | >associative_append @Heq
262 | >Ht whd in match (option_hd ??) in ⊢ (??%?); whd in match (tail ??) in ⊢ (??%?);
265 [ normalize >rev_append_def >rev_append_def >reverse_append %
266 | #r1 #rs1 normalize >rev_append_def >rev_append_def >reverse_append % ]
267 | #c1 #csr1 normalize >rev_append_def >rev_append_def >reverse_append % ]
270 #H whd in match (plus ??); >H @eq_f @eq_f2 %
275 lemma le_to_eq : ∀m,n.m ≤ n → ∃k. n = m + k. /3 by plus_minus, ex_intro/
278 lemma minus_tech : ∀a,b.a + b - a = b. // qed.
280 lemma binaryTM_phase0_midtape :
281 ∀sig,M,t,q,ls,a,rs,ch,k.
282 halt sig M q=false → S (FS_crd sig) ≤ k →
283 t = mk_tape ? ls (option_hd ? (bin_char ? a)) (tail ? (bin_char sig a@rs)) →
284 loopM ? (mk_binaryTM sig M) k
285 (mk_config ?? (〈q,bin0,ch,FS_crd sig〉) t)
286 = loopM ? (mk_binaryTM sig M) (k - S (FS_crd sig))
287 (mk_config ?? (〈q,bin1,Some ? a,FS_crd sig〉)
288 (mk_tape ? (reverse ? (bin_char ? a)@ls) (option_hd ? rs) (tail ? rs))). [|*:@le_S //]
289 #sig #M #t #q #ls #a #rs #ch #k #Hhalt #Hk #Ht
290 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
291 cut (∃c,cl.bin_char sig a = c::cl) [@daemon] * #c * #cl #Ha >Ha
292 cut (FS_crd sig = |bin_char sig a|) [@daemon] #Hlen
293 @(trans_eq ?? (loopM ? (mk_binaryTM ? M) (S (|c::cl|) + k0)
294 (mk_config ?? 〈q,bin0,〈ch,|c::cl|〉〉 t)))
295 [ /2 by O/ | @eq_f2 // @eq_f2 // @eq_f <Ha >Hlen % ]
296 >(binaryTM_phase0_midtape_aux ? M q ls a rs ? ? (c::cl) [ ] t ch) //
297 [| normalize #Hfalse @False_ind cases (not_le_Sn_O ?) /2/
298 | <Ha (* |bin_char sig ?| = FS_crd sig *) @daemon
305 lemma binaryTM_phase0_None_None :
306 ∀sig,M,t,q,ch,k,n,qn,mv.
307 O < n → n < 2*FS_crd sig → O < k →
309 current ? t = None ? →
310 〈qn,None ?,mv〉 = trans sig M 〈q,None ?〉 →
311 loopM ? (mk_binaryTM sig M) k (mk_config ?? (〈q,bin0,ch,n〉) t)
312 = loopM ? (mk_binaryTM sig M) (k-1)
313 (mk_config ?? (〈q,bin2,None ?,to_initN O ??〉) t). [2,3: /2 by transitive_lt/ ]
314 #sig #M #t #q #ch #k #n #qn #mv #HOn #Hn #Hk #Hhalt
315 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
316 cases (le_to_eq … HOn) #n0 #Hn0 destruct (Hn0)
318 [ >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin2 // /2 by refl, transitive_lt/
319 | #r0 #rs0 >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin2 // /2 by refl, transitive_lt/
320 | #l0 #ls0 >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin2 // /2 by refl, transitive_lt/
321 | #ls #cur #rs normalize in ⊢ (%→?); #H destruct (H) ]
324 lemma binaryTM_phase0_None_Some :
325 ∀sig,M,t,q,ch,k,n,qn,chn,mv.
326 O < n → n < 2*FS_crd sig → O < k →
328 current ? t = None ? →
329 〈qn,Some ? chn,mv〉 = trans sig M 〈q,None ?〉 →
330 loopM ? (mk_binaryTM sig M) k (mk_config ?? (〈q,bin0,ch,n〉) t)
331 = loopM ? (mk_binaryTM sig M) (k-1)
332 (mk_config ?? (〈q,bin4,None ?,to_initN O ??〉) (tape_move ? t R)). [2,3: /2 by transitive_lt/ ]
333 #sig #M #t #q #ch #k #n #qn #chn #mv #HOn #Hn #Hk #Hhalt
334 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
335 cases (le_to_eq … HOn) #n0 #Hn0 destruct (Hn0)
337 [ >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin4 // /2 by refl, transitive_lt/
338 | #r0 #rs0 >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin4 // /2 by refl, transitive_lt/
339 | #l0 #ls0 >loopM_unfold >loop_S_false [|@Hhalt] #Hcur #Htrans >binaryTM_bin0_bin4 // /2 by refl, transitive_lt/
340 | #ls #cur #rs normalize in ⊢ (%→?); #H destruct (H) ]
343 lemma binaryTM_bin1_O :
345 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin1,ch,O〉) t)
346 = mk_config ?? (〈q,bin2,ch,to_initN (FS_crd sig) ??〉) t. [2,3:/2 by lt_S_to_lt/]
350 lemma binaryTM_bin1_S :
351 ∀sig,M,t,q,ch,k. S k <S (2*FS_crd sig) →
352 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin1,ch,S k〉) t)
353 = mk_config ?? (〈q,bin1,ch,to_initN k ??〉) (tape_move ? t L). [2,3:@le_S /2 by lt_S_to_lt/]
354 #sig #M #t #q #ch #k #HSk %
357 lemma binaryTM_phase1 :
358 ∀sig,M,q,ls1,ls2,cur,rs,ch,k.
359 S (FS_crd sig) ≤ k → |ls1| = FS_crd sig → (cur = None ? → rs = [ ]) →
360 loopM ? (mk_binaryTM sig M) k
361 (mk_config ?? (〈q,bin1,ch,FS_crd sig〉) (mk_tape ? (ls1@ls2) cur rs))
362 = loopM ? (mk_binaryTM sig M) (k - S (FS_crd sig))
363 (mk_config ?? (〈q,bin2,ch,FS_crd sig〉)
364 (mk_tape ? ls2 (option_hd ? (reverse ? ls1@option_cons ? cur rs))
365 (tail ? (reverse ? ls1@option_cons ? cur rs)))). [2,3:/2 by O/]
366 cut (∀sig,M,q,ls1,ls2,ch,k,n,cur,rs.
367 |ls1| = n → n<S (2*FS_crd sig) → (cur = None ? → rs = [ ]) →
368 loopM ? (mk_binaryTM sig M) (S n + k)
369 (mk_config ?? (〈q,bin1,ch,n〉) (mk_tape ? (ls1@ls2) cur rs))
370 = loopM ? (mk_binaryTM sig M) k
371 (mk_config ?? (〈q,bin2,ch,FS_crd sig〉)
372 (mk_tape ? ls2 (option_hd ? (reverse ? ls1@option_cons ? cur rs))
373 (tail ? (reverse ? ls1@option_cons ? cur rs))))) [1,2:@le_S //]
374 [ #sig #M #q #ls1 #ls2 #ch #k elim ls1
375 [ #n normalize in ⊢ (%→?); #cur #rs #Hn <Hn #Hcrd #Hcur >loopM_unfold >loop_S_false [| % ]
376 >binaryTM_bin1_O cases cur in Hcur;
377 [ #H >(H (refl ??)) -H %
379 | #l0 #ls0 #IH * [ #cur #rs normalize in ⊢ (%→?); #H destruct (H) ]
380 #n #cur #rs normalize in ⊢ (%→?); #H destruct (H) #Hlt #Hcur
381 >loopM_unfold >loop_S_false [|%] >binaryTM_bin1_S
382 <(?:mk_tape ? (ls0@ls2) (Some ? l0) (option_cons ? cur rs) =
383 tape_move FinBool (mk_tape FinBool ((l0::ls0)@ls2) cur rs) L)
384 [| cases cur in Hcur; [ #H >(H ?) // | #cur' #_ % ] ]
385 >(?:loop (config FinBool (states FinBool (mk_binaryTM sig M))) (S (|ls0|)+k)
386 (step FinBool (mk_binaryTM sig M))
387 (λc:config FinBool (states FinBool (mk_binaryTM sig M))
388 .halt FinBool (mk_binaryTM sig M)
389 (cstate FinBool (states FinBool (mk_binaryTM sig M)) c))
390 (mk_config FinBool (states FinBool (mk_binaryTM sig M))
391 〈q,bin1,ch,to_initN (|ls0|) ?
392 (le_S ?? (lt_S_to_lt (|ls0|) (S (2*FS_crd sig)) Hlt))〉
393 (mk_tape FinBool (ls0@ls2) (Some FinBool l0) (option_cons FinBool cur rs)))
394 = loopM FinBool (mk_binaryTM sig M) k
395 (mk_config FinBool (states FinBool (mk_binaryTM sig M))
396 〈q,bin2,〈ch,FS_crd sig〉〉
398 (option_hd FinBool (reverse FinBool ls0@l0::option_cons FinBool cur rs))
399 (tail FinBool (reverse FinBool ls0@l0::option_cons FinBool cur rs)))))
401 | >(?: l0::option_cons ? cur rs = option_cons ? (Some ? l0) (option_cons ? cur rs)) [| % ]
402 @trans_eq [|| @(IH ??? (refl ??)) [ /2 by lt_S_to_lt/ | #H destruct (H) ] ]
405 >reverse_cons >associative_append %
407 | #Hcut #sig #M #q #ls1 #ls2 #cur #rs #ch #k #Hk #Hlen
408 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech @Hcut // ]
411 lemma binaryTM_bin2_O :
412 ∀sig,M,t,q,qn,ch,chn,mv.
413 〈qn,chn,mv〉 = trans sig M 〈q,ch〉 →
414 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin2,ch,O〉) t)
415 = mk_config ?? (〈qn,bin3,ch,to_initN (displ_of_move sig mv) ??〉) t.[2,3:/2 by lt_S_to_lt,le_S_S/]
416 #sig #M #t #q #qn #ch #chn #mv #Htrans
417 whd in match (step ???); whd in match (trans ???); <Htrans %
420 lemma binaryTM_bin2_S_None :
421 ∀sig,M,t,q,qn,ch,mv,k.
422 k < S (2*FS_crd sig) →
423 〈qn,None ?,mv〉 = trans sig M 〈q,ch〉 →
424 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin2,ch,S k〉) t)
425 = mk_config ?? (〈q,bin2,ch,k〉) (tape_move ? t R).
426 [2,3: @le_S_S /2 by lt_to_le/ ]
427 #sig #M #t #q #qn #ch #mv #k #Hk #Htrans
428 whd in match (step ???); whd in match (trans ???); <Htrans %
431 lemma binaryTM_bin2_S_Some :
432 ∀sig,M,t,q,qn,ch,chn,mv,k.
433 k< S (2*FS_crd sig) →
434 〈qn,Some ? chn,mv〉 = trans sig M 〈q,ch〉 →
435 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin2,ch,S k〉) t)
436 = mk_config ?? (〈q,bin2,ch,k〉) (tape_move ? (tape_write ? t (Some ? (FS_nth ? k == Some ? chn))) R).
437 [2,3: @le_S_S /2 by lt_to_le/ ]
438 #sig #M #t #q #qn #ch #chn #mv #k #Hk #Htrans
439 whd in match (step ???); whd in match (trans ???); <Htrans %
442 let rec iter (T:Type[0]) f n (t:T) on n ≝
443 match n with [ O ⇒ t | S n0 ⇒ iter T f n0 (f t) ].
445 lemma binaryTM_phase2_None :∀sig,M,q,ch,qn,mv,k,n. S n ≤ k →
446 ∀t.n≤S (2*FS_crd sig) →
447 〈qn,None ?,mv〉 = trans sig M 〈q,ch〉 →
448 loopM ? (mk_binaryTM sig M) k
449 (mk_config ?? (〈q,bin2,ch,n〉) t)
450 = loopM ? (mk_binaryTM sig M) (k - S n)
451 (mk_config ?? (〈qn,bin3,ch,to_initN (displ_of_move sig mv) ??〉)
452 (iter ? (λt0.tape_move ? t0 R) n t)). [2,3: @le_S_S /2 by lt_S_to_lt/]
453 #sig #M #q #ch #qn #mv #k #n #Hk
454 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
456 [ #t #Hle #Htrans >loopM_unfold >loop_S_false //
457 >(binaryTM_bin2_O … Htrans) //
458 | #n0 #IH #t #Hn0 #Htrans >loopM_unfold >loop_S_false //
459 >(binaryTM_bin2_S_None … Htrans) @(trans_eq ???? (IH …)) //
463 lemma binaryTM_phase2_Some_of : ∀sig,M,q,ch,qn,chn,mv,ls,k.
464 S (FS_crd sig) ≤ k → 〈qn,Some ? chn,mv〉 = trans sig M 〈q,ch〉 →
465 loopM ? (mk_binaryTM sig M) k
466 (mk_config ?? (〈q,bin2,ch,FS_crd sig〉) (mk_tape ? ls (None ?) [ ]))
467 = loopM ? (mk_binaryTM sig M) (k - S (FS_crd sig))
468 (mk_config ?? (〈qn,bin3,ch,displ_of_move sig mv〉)
469 (mk_tape ? (reverse ? (bin_char sig chn)@ls) (None ?) [ ])). [2,3:@le_S_S //]
470 cut (∀sig,M,q,ch,qn,chn,mv,ls,k,n.
471 S n ≤ k → 〈qn,Some ? chn,mv〉 = trans sig M 〈q,ch〉 →
472 ∀csl. n <S (2*FS_crd sig) →
473 |csl| + n = FS_crd sig →
474 (∃fs.bin_char sig chn = reverse ? csl@fs) →
475 loopM ? (mk_binaryTM sig M) k
476 (mk_config ?? (〈q,bin2,ch,n〉) (mk_tape ? (csl@ls) (None ?) [ ]))
477 = loopM ? (mk_binaryTM sig M) (k - S n)
478 (mk_config ?? (〈qn,bin3,ch,displ_of_move sig mv〉)
479 (mk_tape ? (reverse ? (bin_char sig chn)@ls) (None ?) [ ]))) [1,2:@le_S_S //]
480 [ #sig #M #q #ch #qn #chn #mv #ls #k #n #Hk
481 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
483 [ #csl #Hcount #Hcrd * #fs #Hfs >loopM_unfold >loop_S_false // <loopM_unfold
485 [ cases fs in Hfs; // #f0 #fs0 #H lapply (eq_f ?? (length ?) … H)
486 >length_append >(?:|bin_char sig chn| = FS_crd sig) [|@daemon]
487 <Hcrd >length_reverse #H1 cut (O = |f0::fs0|) [ /2/ ]
488 normalize #H1 destruct (H1) ]
489 #H destruct (H) >append_nil in Hfs; #Hfs
490 >Hfs >reverse_reverse >(binaryTM_bin2_O … Htrans) //
491 | #n0 #IH #csl #Hcount #Hcrd * #fs #Hfs
492 >loopM_unfold >loop_S_false // <loopM_unfold
493 >(?: step FinBool (mk_binaryTM sig M)
494 (mk_config FinBool (states FinBool (mk_binaryTM sig M)) 〈q,bin2,〈ch,S n0〉〉
495 (mk_tape FinBool (csl@ls) (None FinBool) []))
496 = mk_config ?? (〈q,bin2,ch,n0〉)
497 (tape_move ? (tape_write ?
498 (mk_tape ? (csl@ls) (None ?) [ ]) (Some ? (FS_nth ? n0 == Some ? chn))) R))
499 [| /2 by lt_S_to_lt/ | @(binaryTM_bin2_S_Some … Htrans) ]
500 >(?: tape_move ? (tape_write ???) ? =
501 mk_tape ? (((FS_nth ? n0 == Some sig chn)::csl)@ls) (None ?) [ ])
502 [| cases csl // cases ls // ]
504 [ #Hfalse cut (|bin_char ? chn| = |csl|) [ >Hfalse >length_append >length_reverse // ]
505 -Hfalse >(?:|bin_char sig chn| = FS_crd sig) [|@daemon]
506 <Hcrd in ⊢ (%→?); >(?:|csl| = |csl|+ O) in ⊢ (???%→?); //
507 #Hfalse cut (S n0 = O) /2 by injective_plus_r/ #H destruct (H)
509 cut (bin_char ? chn = reverse ? csl@(FS_nth ? n0 == Some ? chn)::fs0) [@daemon]
510 -Hbinchar #Hbinchar >Hbinchar @(trans_eq ???? (IH …)) //
511 [ %{fs0} >reverse_cons >associative_append @Hbinchar
512 | whd in ⊢ (??%?); /2 by / ]
513 @eq_f @eq_f @eq_f3 //
516 | #Hcut #sig #M #q #ch #qn #chn #mv #ls #k #Hk #Htrans
518 [3: @(trans_eq ???? (Hcut ??????? ls ? (FS_crd sig) ? Htrans …)) //
519 [3:@([ ]) | %{(bin_char ? chn)} % | % ]
524 lemma binaryTM_phase2_Some_ow : ∀sig,M,q,ch,qn,chn,mv,ls,k,cs,rs.
525 S (FS_crd sig) ≤ k → 〈qn,Some ? chn,mv〉 = trans sig M 〈q,ch〉 →
527 loopM ? (mk_binaryTM sig M) k
528 (mk_config ?? (〈q,bin2,ch,FS_crd sig〉)
529 (mk_tape ? ls (option_hd ? (cs@rs)) (tail ? (cs@rs))))
530 = loopM ? (mk_binaryTM sig M) (k - S (FS_crd sig))
531 (mk_config ?? (〈qn,bin3,ch,displ_of_move sig mv〉)
532 (mk_tape ? (reverse ? (bin_char sig chn)@ls) (option_hd ? rs) (tail ? rs))). [2,3:@le_S_S /2 by O/]
533 cut (∀sig,M,q,ch,qn,chn,mv,ls,rs,k,csr.
534 〈qn,Some ? chn,mv〉 = trans sig M 〈q,ch〉 →
535 ∀csl.|csr|<S (2*FS_crd sig) →
536 |csl@csr| = FS_crd sig →
537 (∃fs.bin_char sig chn = reverse ? csl@fs) →
538 loopM ? (mk_binaryTM sig M) (S (|csr|) + k)
539 (mk_config ?? (〈q,bin2,ch,|csr|〉)
540 (mk_tape ? (csl@ls) (option_hd ? (csr@rs)) (tail ? (csr@rs))))
541 = loopM ? (mk_binaryTM sig M) k
542 (mk_config ?? (〈qn,bin3,ch,displ_of_move sig mv〉)
543 (mk_tape ? (reverse ? (bin_char sig chn)@ls) (option_hd ? rs) (tail ? rs)))) [1,2: @le_S_S /2 by le_S/]
544 [ #sig #M #q #ch #qn #chn #mv #ls #rs #k #csr #Htrans elim csr
545 [ #csl #Hcount #Hcrd * #fs #Hfs >loopM_unfold >loop_S_false // normalize in match (length ? [ ]);
546 >(binaryTM_bin2_O … Htrans) <loopM_unfold @eq_f @eq_f @eq_f3 //
547 cases fs in Hfs; // #f0 #fs0 #H lapply (eq_f ?? (length ?) … H)
548 >length_append >(?:|bin_char sig chn| = FS_crd sig) [|@daemon]
549 <Hcrd >length_reverse #H1 cut (O = |f0::fs0|) [ /2/ ]
550 normalize #H1 destruct (H1)
551 | #b0 #bs0 #IH #csl #Hcount #Hcrd * #fs #Hfs
552 >loopM_unfold >loop_S_false // >(binaryTM_bin2_S_Some … Htrans)
553 >(?: tape_move ? (tape_write ???) ? =
554 mk_tape ? (((FS_nth ? (|bs0|)==Some sig chn)::csl)@ls)
555 (option_hd ? (bs0@rs)) (tail ? (bs0@rs)))
556 in match (tape_move ? (tape_write ???) ?);
557 [| cases bs0 // cases rs // ] @IH
558 [ whd in Hcount:(?%?); /2 by lt_S_to_lt/
559 | <Hcrd >length_append >length_append normalize //
561 [ #Hfalse cut (|bin_char ? chn| = |csl|) [ >Hfalse >length_append >length_reverse // ] -Hfalse >(?:|bin_char sig chn| = FS_crd sig) [|@daemon]
562 <Hcrd >length_append normalize >(?:|csl| = |csl|+ O) in ⊢ (???%→?); //
563 #Hfalse cut (S (|bs0|) = O) /2 by injective_plus_r/ #H destruct (H)
565 cut (bin_char ? chn = reverse ? csl@(FS_nth ? (|bs0|) == Some ? chn)::fs0) [@daemon]
566 -Hbinchar #Hbinchar >Hbinchar %{fs0} >reverse_cons >associative_append %
570 | #Hcut #sig #M #q #ch #qn #chn #mv #ls #k #cs #rs #Hk #Htrans #Hcrd
571 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech @trans_eq
572 [3: @(trans_eq ???? (Hcut ??????? ls ?? cs Htrans [ ] …)) //
573 [ normalize % // | normalize @Hcrd | >Hcrd // ]
574 || @eq_f2 [ >Hcrd % | @eq_f2 // @eq_f cases Hcrd // ] ] ]
577 lemma binaryTM_bin3_O :
579 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin3,ch,O〉) t)
580 = mk_config ?? (〈q,bin0,None ?,to_initN (FS_crd sig) ??〉) t. [2,3:@le_S //]
584 lemma binaryTM_bin3_S :
585 ∀sig,M,t,q,ch,k. S k <S (2*FS_crd sig) →
586 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin3,ch,S k〉) t)
587 = mk_config ?? (〈q,bin3,ch,to_initN k ??〉) (tape_move ? t L). [2,3:@le_S /2 by lt_S_to_lt/]
588 #sig #M #t #q #ch #k #HSk %
591 lemma binaryTM_phase3 :∀sig,M,q,ch,k,n.
592 S n ≤ k → n<S (2*FS_crd sig) →
593 ∀t.loopM ? (mk_binaryTM sig M) k
594 (mk_config ?? (〈q,bin3,ch,n〉) t)
595 = loopM ? (mk_binaryTM sig M) (k - S n)
596 (mk_config ?? (〈q,bin0,None ?,FS_crd sig〉)
597 (iter ? (λt0.tape_move ? t0 L) n t)). [2,3: @le_S //]
598 #sig #M #q #ch #k #n #Hk
599 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech elim n
600 [ #Hcrd #t >loopM_unfold >loop_S_false [| % ] >binaryTM_bin3_O //
601 | #n0 #IH #Hlt #t >loopM_unfold >loop_S_false [|%] >binaryTM_bin3_S <IH [|/2 by lt_S_to_lt/]
605 lemma binaryTM_bin4_None :
607 current ? t = None ? →
608 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin4,ch,O〉) t)
609 = mk_config ?? (〈q,bin2,ch,to_initN (FS_crd sig) ??〉) t. [2,3: @le_S //]
610 #sig #M #t #q #ch #Hcur whd in ⊢ (??%?); >Hcur %
613 lemma binaryTM_phase4_write : ∀sig,M,q,ch,k,t.
614 O < k → current ? t = None ? →
615 loopM ? (mk_binaryTM sig M) k
616 (mk_config ?? (〈q,bin4,ch,O〉) t)
617 = loopM ? (mk_binaryTM sig M) (k-1)
618 (mk_config ?? (〈q,bin2,ch,to_initN (FS_crd sig) ??〉) t). [2,3: @le_S //]
619 #sig #M #q #ch #k #t #Hk #Hcur
620 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
621 >loopM_unfold >loop_S_false // <loopM_unfold >binaryTM_bin4_None //
624 (* we don't get here any more! *
625 lemma binaryTM_bin4_noextend :
626 ∀sig,M,t,q,ch,cur,qn,mv.
627 current ? t = Some ? cur →
628 〈qn,None ?,mv〉 = trans sig M 〈q,ch〉 →
629 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin4,ch,O〉) t)
630 = mk_config ?? (〈q,bin2,ch,to_initN O ??〉) t. [2,3://]
631 #sig #M #t #q #ch #cur #qn #mv #Hcur #Htrans
632 whd in ⊢ (??%?); >Hcur whd in ⊢ (??%?);
633 whd in match (trans FinBool ??); <Htrans %
637 lemma binaryTM_bin4_extend :
638 ∀sig,M,t,q,ch,cur,qn,an,mv.
639 current ? t = Some ? cur →
640 〈qn,Some ? an,mv〉 = trans sig M 〈q,ch〉 →
641 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin4,ch,O〉) t)
642 = mk_config ?? (〈q,bin5,ch,to_initN (FS_crd sig) ??〉) (tape_move ? t L). [2,3:@le_S //]
643 #sig #M #t #q #ch #cur #qn #an #mv #Hcur #Htrans
644 whd in ⊢ (??%?); >Hcur whd in ⊢ (??%?);
645 whd in match (trans FinBool ??); <Htrans %
648 lemma binaryTM_phase4_extend : ∀sig,M,q,ch,k,t,cur,qn,an,mv.
649 O < k → current ? t = Some ? cur →
650 〈qn,Some ? an,mv〉 = trans sig M 〈q,ch〉 →
651 loopM ? (mk_binaryTM sig M) k
652 (mk_config ?? (〈q,bin4,ch,O〉) t)
653 = loopM ? (mk_binaryTM sig M) (k-1)
654 (mk_config ?? (〈q,bin5,ch,to_initN (FS_crd sig) ??〉) (tape_move ? t L)). [2,3: @le_S //]
655 #sig #M #q #ch #k #t #cur #qn #an #mv #Hk #Hcur #Htrans
656 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
657 >loopM_unfold >loop_S_false // <loopM_unfold >binaryTM_bin4_extend //
660 lemma binaryTM_bin5_O :
662 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin5,ch,O〉) t)
663 = mk_config ?? (〈q,bin2,ch,to_initN (FS_crd sig) ??〉) (tape_move ? t R). [2,3:@le_S //]
667 lemma binaryTM_bin5_S :
668 ∀sig,M,t,q,ch,k. S k <S (2*FS_crd sig) →
669 step ? (mk_binaryTM sig M) (mk_config ?? (〈q,bin5,ch,S k〉) t)
670 = mk_config ?? (〈q,bin5,ch,to_initN k ??〉) (tape_move ? (tape_write ? t (Some ? false)) L). [2,3:@le_S /2 by lt_S_to_lt/]
671 #sig #M #t #q #ch #k #HSk %
674 (* extends the tape towards the left with an unimportant sequence that will be
675 immediately overwritten *)
676 lemma binaryTM_phase5 :∀sig,M,q,ch,k,n. S n ≤ k →
677 ∀rs.n<S (2*FS_crd sig) →
679 loopM ? (mk_binaryTM sig M) k
680 (mk_config ?? (〈q,bin5,ch,n〉) (mk_tape ? [] (None ?) rs))
681 = loopM ? (mk_binaryTM sig M) (k - S n)
682 (mk_config ?? (〈q,bin2,ch,FS_crd sig〉)
683 (mk_tape ? [] (option_hd ? (bs@rs)) (tail ? (bs@rs)))). [2,3:@le_S //]
684 #sig #M #q #ch #k #n #Hk
685 cases (le_to_eq … Hk) #k0 #Hk0 >Hk0 >minus_tech
687 [ #rs #Hlt %{[]} % // cases rs //
688 | #n0 #IH #rs #Hn0 cases (IH (false::rs) ?) [|/2 by lt_S_to_lt/]
690 %{(bs@[false])} % [ <Hbs >length_append /2 by increasing_to_injective/ ]
691 >loopM_unfold >loop_S_false // >binaryTM_bin5_S
692 >associative_append normalize in match ([false]@?); <IH
693 >loopM_unfold @eq_f @eq_f cases rs //
697 lemma current_None_or_midtape :
698 ∀sig,t.current sig t = None sig ∨ ∃ls,c,rs.t = midtape sig ls c rs.
699 #sig * normalize /2/ #ls #c #rs %2 /4 by ex_intro/
702 lemma state_bin_lift_unfold :
703 ∀sig.∀M:TM sig.∀q:states sig M.
704 state_bin_lift sig M q = 〈q,bin0,None ?,FS_crd sig〉.// qed.
706 axiom current_tape_bin_list :
707 ∀sig,t.current sig t = None ? → current ? (tape_bin_lift sig t) = None ?.
709 lemma binaryTM_loop :
712 loopM sig M i (mk_config ?? q t) = Some ? (mk_config ?? qf tf) →
713 ∃k.loopM ? (mk_binaryTM sig M) k
714 (mk_config ?? (state_bin_lift ? M q) (tape_bin_lift ? t)) =
715 Some ? (mk_config ?? (state_bin_lift ? M qf) (tape_bin_lift ? tf)).
717 [ #t #q #qf #tf #Hcrd change with (None ?) in ⊢ (??%?→?); #H destruct (H)
718 | -i #i #IH #t #q #tf #qf #Hcrd >loopM_unfold
719 lapply (refl ? (halt sig M (cstate ?? (mk_config ?? q t))))
720 cases (halt ?? q) in ⊢ (???%→?); #Hhalt
721 [ >(loop_S_true ??? (λc.halt ?? (cstate ?? c)) (mk_config ?? q t) Hhalt)
722 #H destruct (H) %{1} >loopM_unfold >loop_S_true // ]
723 (* interesting case: more than one step *)
724 >(loop_S_false ??? (λc.halt ?? (cstate ?? c)) (mk_config ?? q t) Hhalt)
725 <loopM_unfold >(config_expand ?? (step ???)) #Hloop
726 lapply (IH … Hloop) [@Hcrd] -IH * #k0 #IH <config_expand in Hloop; #Hloop
727 %{(S (FS_crd sig) + k0)} cases (current_None_or_midtape ? t)
728 (* 1) current = None *)
729 [ #Hcur >state_bin_lift_unfold in ⊢ (??%?);
730 lapply (current_tape_bin_list … Hcur) #Hcur'
731 >binaryTM_phase0_None /2 by monotonic_lt_plus_l/
732 >(?: FS_crd sig + k0 = S (FS_crd sig + k0 - 1)) [|@daemon]
733 >loopM_unfold >loop_S_false // lapply (refl ? t) cases t in ⊢ (???%→?);
734 [4: #ls #c #rs normalize in ⊢ (%→?); #H destruct (H) normalize in Hcur; destruct (Hcur)
735 | #Ht >Ht >binaryTM_bin4_None // <loopM_unfold
740 theorem sem_binaryTM : ∀sig,M.
741 mk_binaryTM sig M ⊫ R_bin_lift ? (R_TM ? M (start ? M)).
742 #sig #M #t #i generalize in match t; -t
743 @(nat_elim1 … i) #m #IH #intape #outc #Hloop