include "turing/multi_universal/compare.ma".
include "turing/multi_universal/par_test.ma".
-
+include "turing/multi_universal/moves_2.ma".
definition Rtc_multi_true ≝
λalpha,test,n,i.λt1,t2:Vector ? (S n).
#Hi0i @sym_eq @Hnth_j @sym_not_eq // ] ]
qed.
-lemma comp_list: ∀S:DeqSet. ∀l1,l2:list S.∀is_endc. ∃l,tl1,tl2.
- l1 = l@tl1 ∧ l2 = l@tl2 ∧ (∀c.c ∈ l = true → is_endc c = false) ∧
- ∀a,tla. tl1 = a::tla →
- is_endc a = true ∨ (is_endc a = false ∧∀b,tlb.tl2 = b::tlb → a≠b).
-#S #l1 #l2 #is_endc elim l1 in l2;
-[ #l2 %{[ ]} %{[ ]} %{l2} normalize %
- [ % [ % // | #c #H destruct (H) ] | #a #tla #H destruct (H) ]
-| #x #l3 #IH cases (true_or_false (is_endc x)) #Hendcx
- [ #l %{[ ]} %{(x::l3)} %{l} normalize
- % [ % [ % // | #c #H destruct (H) ] | #a #tla #H destruct (H) >Hendcx % % ]
- | *
- [ %{[ ]} %{(x::l3)} %{[ ]} normalize %
- [ % [ % // | #c #H destruct (H) ]
- | #a #tla #H destruct (H) cases (is_endc a)
- [ % % | %2 % // #b #tlb #H destruct (H) ]
- ]
- | #y #l4 cases (true_or_false (x==y)) #Hxy
- [ lapply (\P Hxy) -Hxy #Hxy destruct (Hxy)
- cases (IH l4) -IH #l * #tl1 * #tl2 * * * #Hl3 #Hl4 #Hl #IH
- %{(y::l)} %{tl1} %{tl2} normalize
- % [ % [ % //
- | #c cases (true_or_false (c==y)) #Hcy >Hcy normalize
- [ >(\P Hcy) //
- | @Hl ]
- ]
- | #a #tla #Htl1 @(IH … Htl1) ]
- | %{[ ]} %{(x::l3)} %{(y::l4)} normalize %
- [ % [ % // | #c #H destruct (H) ]
- | #a #tla #H destruct (H) cases (is_endc a)
- [ % % | %2 % // #b #tlb #H destruct (H) @(\Pf Hxy) ]
- ]
- ]
- ]
- ]
-]
-qed.
-
-definition match_test ≝ λsrc,dst.λsig:DeqSet.λn,is_endc.λv:Vector ? n.
+definition match_test ≝ λsrc,dst.λsig:DeqSet.λn.λv:Vector ? n.
match (nth src (option sig) v (None ?)) with
[ None ⇒ false
- | Some x ⇒ notb ((is_endc x) ∨ (nth dst (DeqOption sig) v (None ?) == None ?))].
+ | Some x ⇒ notb (nth dst (DeqOption sig) v (None ?) == None ?) ].
-definition match_step ≝ λsrc,dst,sig,n,is_startc,is_endc.
- compare src dst sig n is_endc ·
- (ifTM ?? (partest sig n (match_test src dst sig ? is_endc))
+definition mmove_states ≝ initN 2.
+
+definition mmove0 : mmove_states ≝ mk_Sig ?? 0 (leb_true_to_le 1 2 (refl …)).
+definition mmove1 : mmove_states ≝ mk_Sig ?? 1 (leb_true_to_le 2 2 (refl …)).
+
+definition trans_mmove ≝
+ λi,sig,n,D.
+ λp:mmove_states × (Vector (option sig) (S n)).
+ let 〈q,a〉 ≝ p in match (pi1 … q) with
+ [ O ⇒ 〈mmove1,change_vec ? (S n) (null_action ? n) (〈None ?,D〉) i〉
+ | S _ ⇒ 〈mmove1,null_action sig n〉 ].
+
+definition mmove ≝
+ λi,sig,n,D.
+ mk_mTM sig n mmove_states (trans_mmove i sig n D)
+ mmove0 (λq.q == mmove1).
+
+definition Rm_multi ≝
+ λalpha,n,i,D.λt1,t2:Vector ? (S n).
+ t2 = change_vec ? (S n) t1 (tape_move alpha (nth i ? t1 (niltape ?)) D) i.
+
+lemma sem_move_multi :
+ ∀alpha,n,i,D.i ≤ n →
+ mmove i alpha n D ⊨ Rm_multi alpha n i D.
+#alpha #n #i #D #Hin #int %{2}
+%{(mk_mconfig ? mmove_states n mmove1 ?)}
+[| %
+ [ whd in ⊢ (??%?); @eq_f whd in ⊢ (??%?); @eq_f %
+ | whd >tape_move_multi_def
+ <(change_vec_same … (ctapes …) i (niltape ?))
+ >pmap_change <tape_move_multi_def >tape_move_null_action % ] ]
+ qed.
+
+definition rewind ≝ λsrc,dst,sig,n.
+ parmove src dst sig n L · mmove src sig n R · mmove dst sig n R.
+
+definition R_rewind ≝ λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
+ (∀x,x0,xs,rs.
+ nth src ? int (niltape ?) = midtape sig (xs@[x0]) x rs →
+ ∀ls0,y,y0,target,rs0.|xs| = |target| →
+ nth dst ? int (niltape ?) = midtape sig (target@y0::ls0) y rs0 →
+ outt = change_vec ??
+ (change_vec ?? int (midtape sig [] x0 (reverse ? xs@x::rs)) src)
+ (midtape sig ls0 y0 (reverse ? target@y::rs0)) dst).
+
+theorem accRealize_to_Realize :
+ ∀sig,n.∀M:mTM sig n.∀Rtrue,Rfalse,acc.
+ M ⊨ [ acc: Rtrue, Rfalse ] → M ⊨ Rtrue ∪ Rfalse.
+#sig #n #M #Rtrue #Rfalse #acc #HR #t
+cases (HR t) #k * #outc * * #Hloop
+#Htrue #Hfalse %{k} %{outc} % //
+cases (true_or_false (cstate sig (states sig n M) n outc == acc)) #Hcase
+[ % @Htrue @(\P Hcase) | %2 @Hfalse @(\Pf Hcase) ]
+qed.
+
+lemma sem_rewind : ∀src,dst,sig,n.
+ src ≠ dst → src < S n → dst < S n →
+ rewind src dst sig n ⊨ R_rewind src dst sig n.
+#src #dst #sig #n #Hneq #Hsrc #Hdst
+@(sem_seq_app sig n ????? (sem_parmoveL src dst sig n Hneq Hsrc Hdst) ?)
+[| @(sem_seq_app sig n ????? (sem_move_r_multi …) (sem_move_r_multi …)) //
+ @le_S_S_to_le // ]
+#ta #tb * #tc * * #Htc #_ * #td * whd in ⊢ (%→%→?); #Htd #Htb
+#x #x0 #xs #rs #Hmidta_src #ls0 #y #y0 #target #rs0 #Hlen #Hmidta_dst
+>(Htc ??? Hmidta_src ls0 y (target@[y0]) rs0 ??) in Htd;
+[|>Hmidta_dst //
+|>length_append >length_append >Hlen % ] * #_
+[ whd in ⊢ (%→?); * #x1 * #x2 * *
+ >change_vec_commute in ⊢ (%→?); // >nth_change_vec //
+ cases (reverse sig (xs@[x0])@x::rs)
+ [|#z #zs] normalize in ⊢ (%→?); #H destruct (H)
+| whd in ⊢ (%→?); * #_ #Htb >Htb -Htb FAIL
+
+ normalize in ⊢ (%→?);
+ (sem_parmove_step src dst sig n R Hneq Hsrc Hdst))
+ (acc_sem_if ? n … (sem_partest sig n (match_test src dst sig ?))
+ (sem_seq …
+ (sem_parmoveL ???? Hneq Hsrc Hdst)
+ (sem_inject … dst (le_S_S_to_le … Hdst) (sem_move_r ? )))
+ (sem_nop …)))
+
+
+definition match_step ≝ λsrc,dst,sig,n.
+ compare src dst sig n ·
+ (ifTM ?? (partest sig n (match_test src dst sig ?))
(single_finalTM ??
- (parmove src dst sig n L is_startc · (inject_TM ? (move_r ?) n dst)))
+ (rewind src dst sig n · (inject_TM ? (move_r ?) n dst)))
(nop …)
partest1).
definition R_match_step_false ≝
- λsrc,dst,sig,n,is_endc.λint,outt: Vector (tape sig) (S n).
- ∀ls,x,xs,end,rs.
- nth src ? int (niltape ?) = midtape sig ls x (xs@end::rs) →
- (∀c0. memb ? c0 (x::xs) = true → is_endc c0 = false) → is_endc end = true →
- ((current sig (nth dst (tape sig) int (niltape sig)) = None ?) ∧ outt = int) ∨
+ λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
+ ∀ls,x,xs.
+ nth src ? int (niltape ?) = midtape sig ls x xs →
+ ((current sig (nth dst (tape sig) int (niltape sig)) = None ?) ∧ outt = int) ∨
(∃ls0,rs0,xs0. nth dst ? int (niltape ?) = midtape sig ls0 x rs0 ∧
xs = rs0@xs0 ∧
current sig (nth dst (tape sig) outt (niltape sig)) = None ?) ∨
(∃ls0,rs0.
nth dst ? int (niltape ?) = midtape sig ls0 x (xs@rs0) ∧
- ∀rsj,c.
- rs0 = c::rsj →
+ (* ∀rsj,c.
+ rs0 = c::rsj → *)
outt = change_vec ??
- (change_vec ?? int (midtape sig (reverse ? xs@x::ls) end rs) src)
- (midtape sig (reverse ? xs@x::ls0) c rsj) dst).
+ (change_vec ?? int (mk_tape sig (reverse ? xs@x::ls) (None ?) [ ]) src)
+ (mk_tape sig (reverse ? xs@x::ls0) (option_hd ? rs0) (tail ? rs0)) dst).
+(*definition R_match_step_true ≝
+ λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
+ ∀s,rs.current sig (nth src (tape sig) int (niltape sig)) = Some ? s →
+ current sig (nth dst (tape sig) int (niltape sig)) ≠ None ? ∧
+ (∀s1.current sig (nth dst (tape sig) int (niltape sig)) = Some ? s1 → s ≠ s1 →
+ outt = change_vec ?? int
+ (tape_move_mono … (nth dst ? int (niltape ?)) (〈Some ? s1,R〉)) dst) ∧
+ (∀ls,x,xs,ci,rs,ls0,rs0.
+ nth src ? int (niltape ?) = midtape sig ls x (xs@ci::rs) →
+ nth dst ? int (niltape ?) = midtape sig ls0 x (xs@rs0) →
+ rs0 ≠ [] ∧
+ ∀cj,rs1.rs0 = cj::rs1 →
+ ci ≠ cj →
+ (outt = change_vec ?? int
+ (tape_move_mono … (nth dst ? int (niltape ?)) (〈None ?,R〉)) dst)).
+*)
definition R_match_step_true ≝
- λsrc,dst,sig,n,is_startc,is_endc.λint,outt: Vector (tape sig) (S n).
+ λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
∀s.current sig (nth src (tape sig) int (niltape sig)) = Some ? s →
- current sig (nth dst (tape sig) int (niltape sig)) ≠ None ? ∧
- (is_startc s = true →
- (∀c.c ∈ right ? (nth src (tape sig) int (niltape sig)) = true → is_startc c = false) →
- (∀s1.current sig (nth dst (tape sig) int (niltape sig)) = Some ? s1 → s ≠ s1 →
+ ∃s1.current sig (nth dst (tape sig) int (niltape sig)) = Some ? s1 ∧
+ (left ? (nth src ? int (niltape ?)) = [ ] →
+ (s ≠ s1 →
outt = change_vec ?? int
- (tape_move … (nth dst ? int (niltape ?)) (Some ? 〈s1,R〉)) dst ∧ is_endc s = false) ∧
- (∀ls,x,xs,ci,rs,ls0,rs0.
- nth src ? int (niltape ?) = midtape sig ls x (xs@ci::rs) →
- nth dst ? int (niltape ?) = midtape sig ls0 x (xs@rs0) →
- (∀c0. memb ? c0 (x::xs) = true → is_endc c0 = false) →
- is_endc ci = false ∧ rs0 ≠ [] ∧
- ∀cj,rs1.rs0 = cj::rs1 →
- ci ≠ cj →
- (outt = change_vec ?? int
- (tape_move … (nth dst ? int (niltape ?)) (Some ? 〈x,R〉)) dst ∧ is_endc ci = false))).
-
+ (tape_move_mono … (nth dst ? int (niltape ?)) (〈None ?,R〉)) dst) ∧
+ (∀xs,ci,rs,ls0,rs0.
+ nth src ? int (niltape ?) = midtape sig [] s (xs@ci::rs) →
+ nth dst ? int (niltape ?) = midtape sig ls0 s (xs@rs0) →
+ rs0 ≠ [] ∧
+ ∀cj,rs1.rs0 = cj::rs1 →
+ ci ≠ cj →
+ (outt = change_vec ?? int
+ (tape_move_mono … (nth dst ? int (niltape ?)) (〈None ?,R〉)) dst))).
+
lemma sem_match_step :
- ∀src,dst,sig,n,is_startc,is_endc.src ≠ dst → src < S n → dst < S n →
- match_step src dst sig n is_startc is_endc ⊨
+ ∀src,dst,sig,n.src ≠ dst → src < S n → dst < S n →
+ match_step src dst sig n ⊨
[ inr ?? (inr ?? (inl … (inr ?? start_nop))) :
- R_match_step_true src dst sig n is_startc is_endc,
- R_match_step_false src dst sig n is_endc ].
-#src #dst #sig #n #is_startc #is_endc #Hneq #Hsrc #Hdst
-@(acc_sem_seq_app sig n … (sem_compare src dst sig n is_endc Hneq Hsrc Hdst)
- (acc_sem_if ? n … (sem_partest sig n (match_test src dst sig ? is_endc))
+ R_match_step_true src dst sig n,
+ R_match_step_false src dst sig n ].
+#src #dst #sig #n #Hneq #Hsrc #Hdst
+@(acc_sem_seq_app sig n … (sem_compare src dst sig n Hneq Hsrc Hdst)
+ (acc_sem_if ? n … (sem_partest sig n (match_test src dst sig ?))
(sem_seq …
- (sem_parmoveL ???? is_startc Hneq Hsrc Hdst)
+ (sem_parmoveL ???? Hneq Hsrc Hdst)
(sem_inject … dst (le_S_S_to_le … Hdst) (sem_move_r ? )))
(sem_nop …)))
-[#ta #tb #tc * #Hcomp1 #Hcomp2 * #td * * #Htest #Htd >Htd -Htd
- * #te * #Hte #Htb whd
- #s #Hcurta_src %
- [ lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
+[#ta #tb #tc * #Hcomp1 #Hcomp2 * #td * #Htest
+ * #te * #Hte #Htb #s #Hcurta_src whd
+ cut (∃s1.current sig (nth dst (tape sig) ta (niltape sig))=Some sig s1)
+ [ lapply Hcomp1 -Hcomp1
+ lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
+ cases (current ? (nth dst ? ta (niltape ?))) in ⊢ (???%→%);
+ [ #Hcurta_dst #Hcomp1 >Hcomp1 in Htest; // *
+ change with (vec_map ?????) in match (current_chars ???); whd in ⊢ (??%?→?);
+ <(nth_vec_map ?? (current ?) src ? ta (niltape ?))
+ <(nth_vec_map ?? (current ?) dst ? ta (niltape ?))
+ >Hcurta_src >Hcurta_dst whd in ⊢ (??%?→?); #H destruct (H)
+ | #s1 #_ #_ %{s1} % ] ]
+ * #s1 #Hcurta_dst %{s1} % // #Hleftta %
+ [ #Hneqss1 -Hcomp2 cut (tc = ta)
+ [@Hcomp1 %1 %1 >Hcurta_src >Hcurta_dst @(not_to_not … Hneqss1) #H destruct (H) //]
+ #H destruct (H) -Hcomp1 cut (td = ta)
+ [ cases Htest -Htest // ] #Htdta destruct (Htdta)
+ cases Hte -Hte #Hte #_
+ cases (current_to_midtape … Hcurta_src) #ls * #rs #Hmidta_src
+ cases (current_to_midtape … Hcurta_dst) #ls0 * #rs0 #Hmidta_dst
+ >Hmidta_src in Hleftta; normalize in ⊢ (%→?); #Hls destruct (Hls)
+ >(Hte s [ ] rs Hmidta_src ls0 s1 [ ] rs0 (refl ??) Hmidta_dst) in Htb;
+ * whd in ⊢ (%→?);
+ mid
+
+ in Htb;
+ cut (te = ta)
+ [ cases Htest -Htest #Htest #Htdta <Htdta @Hte %1 >Htdta @Hcurta_src %{s} % //]
+ -Hte #H destruct (H) %
+ [cases Htb * #_ #Hmove #Hmove1 @(eq_vec … (niltape … ))
+ #i #Hi cases (decidable_eq_nat i dst) #Hidst
+ [ >Hidst >nth_change_vec // cases (current_to_midtape … Hcurta_dst)
+ #ls * #rs #Hta_mid >(Hmove … Hta_mid) >Hta_mid cases rs //
+ | >nth_change_vec_neq [|@sym_not_eq //] @sym_eq @Hmove1 @sym_not_eq // ]
+ | whd in Htest:(??%?); >(nth_vec_map ?? (current sig)) in Hcurta_src; #Hcurta_src
+ >Hcurta_src in Htest; whd in ⊢ (??%?→?);
+ cases (is_endc s) // whd in ⊢ (??%?→?); #H @sym_eq //
+ ]
+ <(nth_vec_map ?? (current ?) dst ? tc (niltape ?))
+ >Hcurta_src normalize
+ lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
cases (current ? (nth dst ? ta (niltape ?))) in ⊢ (???%→%);
- [| #c #_ % #Hfalse destruct (Hfalse) ]
+ [| #s1 #Hcurta_dst %
+ [ % #Hfalse destruct (Hfalse)
+ | #s1' #Hs1 destruct (Hs1) #Hneqss1 -Hcomp2
+ cut (tc = ta)
+ [@Hcomp1 %1 %1 >Hcurta_src >Hcurta_dst @(not_to_not … Hneqss1) #H destruct (H) //]
+ #H destruct (H) -Hcomp1 cases Hte -Hte #_ #Hte
+ cut (te = ta) [ cases Htest -Htest #Htest #Htdta <Htdta @Hte %1 %{s} % //] -Hte #H destruct (H) %
+ [cases Htb * #_ #Hmove #Hmove1 @(eq_vec … (niltape … ))
+ #i #Hi cases (decidable_eq_nat i dst) #Hidst
+ [ >Hidst >nth_change_vec // cases (current_to_midtape … Hcurta_dst)
+ #ls * #rs #Hta_mid >(Hmove … Hta_mid) >Hta_mid cases rs //
+ | >nth_change_vec_neq [|@sym_not_eq //] @sym_eq @Hmove1 @sym_not_eq // ]
+ | whd in Htest:(??%?); >(nth_vec_map ?? (current sig)) in Hcurta_src; #Hcurta_src
+ >Hcurta_src in Htest; whd in ⊢ (??%?→?);
+ cases (is_endc s) // whd in ⊢ (??%?→?); #H @sym_eq //
+ ]
+
+ ]
#Hcurta_dst >Hcomp1 in Htest; [| %2 %2 //]
whd in ⊢ (??%?→?); change with (current ? (niltape ?)) in match (None ?);
<nth_vec_map >Hcurta_src whd in ⊢ (??%?→?); <nth_vec_map
]
]
]
+qed.
+
+definition Pre_match_m ≝
+ λsrc,sig,n,is_startc,is_endc.λt: Vector (tape sig) (S n).
+ ∃start,xs,end.
+ nth src (tape sig) t (niltape sig) = midtape ? [] start (xs@[end]) ∧
+ is_startc start = true ∧
+ (∀c.c ∈ (xs@[end]) = true → is_startc c = false) ∧
+ (∀c.c ∈ (start::xs) = true → is_endc c = false) ∧
+ is_endc end = true.
+
+lemma terminate_match_m :
+ ∀src,dst,sig,n,is_startc,is_endc,t.
+ src ≠ dst → src < S n → dst < S n →
+ Pre_match_m src sig n is_startc is_endc t →
+ match_m src dst sig n is_startc is_endc ↓ t.
+#src #dst #sig #n #is_startc #is_endc #t #Hneq #Hsrc #Hdst * #start * #xs * #end
+* * * * #Hmid_src #Hstart #Hnotstart #Hnotend #Hend
+@(terminate_while … (sem_match_step src dst sig n is_startc is_endc Hneq Hsrc Hdst)) //
+<(change_vec_same … t dst (niltape ?))
+lapply (refl ? (nth dst (tape sig) t (niltape ?)))
+cases (nth dst (tape sig) t (niltape ?)) in ⊢ (???%→?);
+[ #Htape_dst % #t1 whd in ⊢ (%→?); >nth_change_vec_neq [|@sym_not_eq //]
+ >Hmid_src #HR cases (HR ? (refl ??)) -HR
+ >nth_change_vec // >Htape_dst normalize in ⊢ (%→?);
+ * #H @False_ind @H %
+| #x0 #xs0 #Htape_dst % #t1 whd in ⊢ (%→?); >nth_change_vec_neq [|@sym_not_eq //]
+ >Hmid_src #HR cases (HR ? (refl ??)) -HR
+ >nth_change_vec // >Htape_dst normalize in ⊢ (%→?);
+ * #H @False_ind @H %
+| #x0 #xs0 #Htape_dst % #t1 whd in ⊢ (%→?); >nth_change_vec_neq [|@sym_not_eq //]
+ >Hmid_src #HR cases (HR ? (refl ??)) -HR
+ >nth_change_vec // >Htape_dst normalize in ⊢ (%→?);
+ * #H @False_ind @H %
+| #ls #s #rs lapply s -s lapply ls -ls lapply Hmid_src lapply t -t elim rs
+ [#t #Hmid_src #ls #s #Hmid_dst % #t1 whd in ⊢ (%→?); >nth_change_vec_neq [|@sym_not_eq //]
+ >Hmid_src >nth_change_vec // >Hmid_dst #HR cases (HR ? (refl ??)) -HR #_
+ #HR cases (HR Hstart Hnotstart)
+ cases (true_or_false (start == s)) #Hs
+ [ lapply (\P Hs) -Hs #Hs <Hs #_ #Htrue
+ cut (∃ci,xs1.xs@[end] = ci::xs1)
+ [ cases xs
+ [ %{end} %{[]} %
+ | #x1 #xs1 %{x1} %{(xs1@[end])} % ] ] * #ci * #xs1 #Hxs
+ >Hxs in Htrue; #Htrue
+ cases (Htrue [ ] start [ ] ? xs1 ? [ ] (refl ??) (refl ??) ?)
+ [ * #_ * #H @False_ind @H % ]
+ #c0 #Hc0 @Hnotend >(memb_single … Hc0) @memb_hd
+ | lapply (\Pf Hs) -Hs #Hs #Htrue #_
+ cases (Htrue ? (refl ??) Hs) -Htrue #Ht1 #_ %
+ #t2 whd in ⊢ (%→?); #HR cases (HR start ?)
+ [ >Ht1 >nth_change_vec // normalize in ⊢ (%→?); * #H @False_ind @H %
+ | >Ht1 >nth_change_vec_neq [|@sym_not_eq //]
+ >nth_change_vec_neq [|@sym_not_eq //] >Hmid_src % ]
+ ]
+ |#r0 #rs0 #IH #t #Hmid_src #ls #s #Hmid_dst % #t1 whd in ⊢ (%→?);
+ >nth_change_vec_neq [|@sym_not_eq //] >Hmid_src
+ #Htrue cases (Htrue ? (refl ??)) -Htrue #_ #Htrue
+ <(change_vec_same … t1 dst (niltape ?))
+ cases (Htrue Hstart Hnotstart) -Htrue
+ cases (true_or_false (start == s)) #Hs
+ [ lapply (\P Hs) -Hs #Hs <Hs #_ #Htrue
+ cut (∃ls0,xs0,ci,rs,rs0.
+ nth src ? t (niltape ?) = midtape sig [ ] start (xs0@ci::rs) ∧
+ nth dst ? t (niltape ?) = midtape sig ls0 s (xs0@rs0) ∧
+ (is_endc ci = true ∨ (is_endc ci = false ∧ (∀b,tlb.rs0 = b::tlb → ci ≠ b))))
+ [cases (comp_list ? (xs@[end]) (r0::rs0) is_endc) #xs0 * #xs1 * #xs2
+ * * * #Hxs #Hrs #Hxs0notend #Hcomp >Hrs
+ cut (∃y,ys. xs1 = y::ys)
+ [ lapply Hxs0notend lapply Hxs lapply xs0 elim xs
+ [ *
+ [ normalize #Hxs1 <Hxs1 #_ %{end} %{[]} %
+ | #z #zs normalize in ⊢ (%→?); #H destruct (H) #H
+ lapply (H ? (memb_hd …)) -H >Hend #H1 destruct (H1)
+ ]
+ | #y #ys #IH0 *
+ [ normalize in ⊢ (%→?); #Hxs1 <Hxs1 #_ %{y} %{(ys@[end])} %
+ | #z #zs normalize in ⊢ (%→?); #H destruct (H) #Hmemb
+ @(IH0 ? e0 ?) #c #Hc @Hmemb @memb_cons // ] ] ] * #y * #ys #Hxs1
+ >Hxs1 in Hxs; #Hxs >Hmid_src >Hmid_dst >Hxs >Hrs
+ %{ls} %{xs0} %{y} %{ys} %{xs2}
+ % [ % // | @Hcomp // ] ]
+ * #ls0 * #xs0 * #ci * #rs * #rs0 * * #Hmid_src' #Hmid_dst' #Hcomp
+ <Hmid_src in Htrue; >nth_change_vec // >Hs #Htrue destruct (Hs)
+ lapply (Htrue ??????? Hmid_src' Hmid_dst' ?) -Htrue
+ [ #c0 #Hc0 @Hnotend cases (orb_true_l … Hc0) -Hc0 #Hc0
+ [ whd in ⊢ (??%?); >Hc0 %
+ | @memb_cons >Hmid_src in Hmid_src'; #Hmid_src' destruct (Hmid_src')
+ lapply e0 -e0 @(list_elim_left … rs)
+ [ #e0 destruct (e0) lapply (append_l1_injective_r ?????? e0) //
+ | #x1 #xs1 #_ >append_cons in ⊢ (???%→?);
+ <associative_append #e0 lapply (append_l1_injective_r ?????? e0) //
+ #e1 >e1 @memb_append_l1 @memb_append_l1 // ] ]
+ | * * #Hciendc cases rs0 in Hcomp;
+ [ #_ * #H @False_ind @H %
+ | #r1 #rs1 * [ >Hciendc #H destruct (H) ]
+ * #_ #Hcomp lapply (Hcomp ?? (refl ??)) -Hcomp #Hcomp #_ #Htrue
+ cases (Htrue ?? (refl ??) Hcomp) #Ht1 #_ >Ht1 @(IH ?? (s::ls) r0)
+ [ >nth_change_vec_neq [|@sym_not_eq //]
+ >nth_change_vec_neq [|@sym_not_eq //] @Hmid_src
+ | >nth_change_vec // >Hmid_dst % ] ] ]
+ | >Hmid_dst >nth_change_vec // lapply (\Pf Hs) -Hs #Hs #Htrue #_
+ cases (Htrue ? (refl ??) Hs) #Ht1 #_ >Ht1 @(IH ?? (s::ls) r0)
+ [ >nth_change_vec_neq [|@sym_not_eq //]
+ >nth_change_vec_neq [|@sym_not_eq //] @Hmid_src
+ | >nth_change_vec // ] ] ] ]
qed.
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projects / helm.git / blobdiff