(* *)
(**************************************************************************)
+include "turing/simple_machines.ma".
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).
- (∃c. current alpha (nth i ? t1 (niltape ?)) = Some ? c ∧ test c = true) ∧ t2 = t1.
-
-definition Rtc_multi_false ≝
- λalpha,test,n,i.λt1,t2:Vector ? (S n).
- (∀c. current alpha (nth i ? t1 (niltape ?)) = Some ? c → test c = false) ∧ t2 = t1.
+lemma eq_vec_change_vec : ∀sig,n.∀v1,v2:Vector sig n.∀i,t,d.
+ nth i ? v2 d = t →
+ (∀j.i ≠ j → nth j ? v1 d = nth j ? v2 d) →
+ v2 = change_vec ?? v1 t i.
+#sig #n #v1 #v2 #i #t #d #H1 #H2 @(eq_vec … d)
+#i0 #Hlt cases (decidable_eq_nat i0 i) #Hii0
+[ >Hii0 >nth_change_vec //
+| >nth_change_vec_neq [|@sym_not_eq //] @sym_eq @H2 @sym_not_eq // ]
+qed.
-lemma sem_test_char_multi :
- ∀alpha,test,n,i.i ≤ n →
- inject_TM ? (test_char ? test) n i ⊨
- [ tc_true : Rtc_multi_true alpha test n i, Rtc_multi_false alpha test n i ].
-#alpha #test #n #i #Hin #int
-cases (acc_sem_inject … Hin (sem_test_char alpha test) int)
-#k * #outc * * #Hloop #Htrue #Hfalse %{k} %{outc} % [ %
-[ @Hloop
-| #Hqtrue lapply (Htrue Hqtrue) * * * #c *
- #Hcur #Htestc #Hnth_i #Hnth_j %
- [ %{c} % //
- | @(eq_vec … (niltape ?)) #i0 #Hi0
- cases (decidable_eq_nat i0 i) #Hi0i
- [ >Hi0i @Hnth_i
- | @sym_eq @Hnth_j @sym_not_eq // ] ] ]
-| #Hqfalse lapply (Hfalse Hqfalse) * * #Htestc #Hnth_i #Hnth_j %
- [ @Htestc
- | @(eq_vec … (niltape ?)) #i0 #Hi0
- cases (decidable_eq_nat i0 i) #Hi0i
- [ >Hi0i @Hnth_i
- | @sym_eq @Hnth_j @sym_not_eq // ] ] ]
+lemma right_mk_tape :
+ ∀sig,ls,c,rs.(c = None ? → ls = [ ] ∨ rs = [ ]) → right ? (mk_tape sig ls c rs) = rs.
+#sig #ls #c #rs cases c // cases ls
+[ cases rs //
+| #l0 #ls0 #H normalize cases (H (refl ??)) #H1 [ destruct (H1) | >H1 % ] ]
qed.
-definition Rm_test_null_true ≝
- λalpha,n,i.λt1,t2:Vector ? (S n).
- current alpha (nth i ? t1 (niltape ?)) ≠ None ? ∧ t2 = t1.
-
-definition Rm_test_null_false ≝
- λalpha,n,i.λt1,t2:Vector ? (S n).
- current alpha (nth i ? t1 (niltape ?)) = None ? ∧ t2 = t1.
+lemma left_mk_tape : ∀sig,ls,c,rs.left ? (mk_tape sig ls c rs) = ls.
+#sig #ls #c #rs cases c // cases ls // cases rs //
+qed.
-lemma sem_test_null_multi : ∀alpha,n,i.i ≤ n →
- inject_TM ? (test_null ?) n i ⊨
- [ tc_true : Rm_test_null_true alpha n i, Rm_test_null_false alpha n i ].
-#alpha #n #i #Hin #int
-cases (acc_sem_inject … Hin (sem_test_null alpha) int)
-#k * #outc * * #Hloop #Htrue #Hfalse %{k} %{outc} % [ %
-[ @Hloop
-| #Hqtrue lapply (Htrue Hqtrue) * * #Hcur #Hnth_i #Hnth_j % //
- @(eq_vec … (niltape ?)) #i0 #Hi0 cases (decidable_eq_nat i0 i) #Hi0i
- [ >Hi0i @sym_eq @Hnth_i | @sym_eq @Hnth_j @sym_not_eq // ] ]
-| #Hqfalse lapply (Hfalse Hqfalse) * * #Hcur #Hnth_i #Hnth_j %
- [ @Hcur
- | @(eq_vec … (niltape ?)) #i0 #Hi0 cases (decidable_eq_nat i0 i) //
- #Hi0i @sym_eq @Hnth_j @sym_not_eq // ] ]
+lemma current_mk_tape : ∀sig,ls,c,rs.current ? (mk_tape sig ls c rs) = c.
+#sig #ls #c #rs cases c // cases ls // cases rs //
qed.
-definition match_test ≝ λsrc,dst.λsig:DeqSet.λn.λv:Vector ? n.
- match (nth src (option sig) v (None ?)) with
- [ None ⇒ false
- | Some x ⇒ notb (nth dst (DeqOption sig) v (None ?) == None ?) ].
+lemma length_tail : ∀A,l.0 < |l| → |tail A l| < |l|.
+#A * normalize //
+qed.
-definition mmove_states ≝ initN 2.
+(*
+[ ] → [ ], l2, 1
+a::al →
+ [ ] → [ ], l1, 2
+ b::bl → match rec(al,bl)
+ x, y, 1 → b::x, y, 1
+ x, y, 2 → a::x, y, 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 …)).
+lemma lists_length_split :
+ ∀A.∀l1,l2:list A.(∃la,lb.(|la| = |l1| ∧ l2 = la@lb) ∨ (|la| = |l2| ∧ l1 = la@lb)).
+#A #l1 elim l1
+[ #l2 %{[ ]} %{l2} % % %
+| #hd1 #tl1 #IH *
+ [ %{[ ]} %{(hd1::tl1)} %2 % %
+ | #hd2 #tl2 cases (IH tl2) #x * #y *
+ [ * #IH1 #IH2 %{(hd2::x)} %{y} % normalize % //
+ | * #IH1 #IH2 %{(hd1::x)} %{y} %2 normalize % // ]
+ ]
+]
+qed.
+
+definition option_cons ≝ λsig.λc:option sig.λl.
+ match c with [ None ⇒ l | Some c0 ⇒ c0::l ].
-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〉 ].
+lemma opt_cons_tail_expand : ∀A,l.l = option_cons A (option_hd ? l) (tail ? l).
+#A * //
+qed.
-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 match_test ≝ λsrc,dst.λsig:DeqSet.λn.λv:Vector ? n.
+ match (nth src (option sig) v (None ?)) with
+ [ None ⇒ false
+ | Some x ⇒ notb (nth dst (DeqOption sig) v (None ?) == None ?) ].
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_strong ≝ 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) ∧
+ (∀x,x0,xs,rs.
+ nth dst ? int (niltape ?) = midtape sig (xs@[x0]) x rs →
+ ∀ls0,y,y0,target,rs0.|xs| = |target| →
+ nth src ? int (niltape ?) = midtape sig (target@y0::ls0) y rs0 →
+ outt = change_vec ??
+ (change_vec ?? int (midtape sig [] x0 (reverse ? xs@x::rs)) dst)
+ (midtape sig ls0 y0 (reverse ? target@y::rs0)) src) ∧
+ (∀x,rs.nth src ? int (niltape ?) = midtape sig [] x rs →
+ ∀ls0,y,rs0.nth dst ? int (niltape ?) = midtape sig ls0 y rs0 →
+ outt = int) ∧
+ (∀x,rs.nth dst ? int (niltape ?) = midtape sig [] x rs →
+ ∀ls0,y,rs0.nth src ? int (niltape ?) = midtape sig ls0 y rs0 →
+ outt = int).
+
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 →
qed.
*)
-lemma sem_rewind : ∀src,dst,sig,n.
+lemma sem_rewind_strong : ∀src,dst,sig,n.
src ≠ dst → src < S n → dst < S n →
- rewind src dst sig n ⊨ R_rewind src dst sig n.
+ rewind src dst sig n ⊨ R_rewind_strong 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_multi … R ?) (sem_move_multi … R ?)) //
@le_S_S_to_le // ]
-#ta #tb * #tc * * #Htc #_ * #td * whd in ⊢ (%→%→?); #Htd #Htb %
+#ta #tb * #tc * * * #Htc1 #Htc2 #_ * #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;
+ >(Htc1 ??? Hmidta_src ls0 y (target@[y0]) rs0 ??) in Htd;
[|>Hmidta_dst //
|>length_append >length_append >Hlen % ]
>change_vec_commute [|@sym_not_eq //]
>rev_append_def >append_nil #Htd >Htd in Htb;
>change_vec_change_vec >nth_change_vec //
cases ls0 [|#l1 #ls1] normalize in match (tape_move ???); //
+| #x #x0 #xs #rs #Hmidta_dst #ls0 #y #y0 #target #rs0 #Hlen #Hmidta_src
+ >(Htc2 ??? Hmidta_dst ls0 y (target@[y0]) rs0 ??) in Htd;
+ [|>Hmidta_src //
+ |>length_append >length_append >Hlen % ]
+ >change_vec_change_vec
+ >change_vec_commute [|@sym_not_eq //]
+ >nth_change_vec //
+ >reverse_append >reverse_single
+ >reverse_append >reverse_single
+ cases ls0 [|#l1 #ls1] normalize in match (tape_move ???);
+ #Htd >Htd in Htb; >change_vec_change_vec >nth_change_vec //
+ >rev_append_def >change_vec_commute // normalize in match (tape_move ???); // ]
| #x #rs #Hmidta_src #ls0 #y #rs0 #Hmidta_dst
- lapply (Htc … Hmidta_src … (refl ??) Hmidta_dst) -Htc #Htc >Htc in Htd;
+ lapply (Htc1 … Hmidta_src … (refl ??) Hmidta_dst) -Htc1 #Htc >Htc in Htd;
>change_vec_commute [|@sym_not_eq //] >change_vec_change_vec
>nth_change_vec_neq [|@sym_not_eq //]
>nth_change_vec // lapply (refl ? ls0) cases ls0 in ⊢ (???%→%);
>nth_change_vec // >change_vec_change_vec
whd in match (tape_move ???);whd in match (tape_move ???); <Hmidta_src
<Hls0 <Hmidta_dst >change_vec_same >change_vec_same //
-]]
+ ] ]
+| #x #rs #Hmidta_dst #ls0 #y #rs0 #Hmidta_src
+ lapply (Htc2 … Hmidta_dst … (refl ??) Hmidta_src) -Htc2 #Htc >Htc in Htd;
+ >change_vec_change_vec >change_vec_commute [|@sym_not_eq //]
+ >nth_change_vec // lapply (refl ? ls0) cases ls0 in ⊢ (???%→%);
+ [ #Hls0 destruct (Hls0) #Htd >Htd in Htb;
+ >nth_change_vec // >change_vec_change_vec
+ whd in match (tape_move ???);whd in match (tape_move ???);
+ <Hmidta_src <Hmidta_dst >change_vec_same >change_vec_same //
+ | #l1 #ls1 #Hls0 destruct (Hls0) #Htd >Htd in Htb;
+ >nth_change_vec // >change_vec_change_vec
+ whd in match (tape_move ???); whd in match (tape_move ???); <Hmidta_src
+ <Hmidta_dst >change_vec_same >change_vec_same //
+ ]
+]
+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 @(Realize_to_Realize … (sem_rewind_strong …)) //
+#ta #tb * * * #H1 #H2 #H3 #H4 % /2 by /
qed.
definition match_step ≝ λsrc,dst,sig,n.
compare src dst sig n ·
(ifTM ?? (partest sig n (match_test src dst sig ?))
(single_finalTM ??
- (rewind src dst sig n · (inject_TM ? (move_r ?) n dst)))
+ (rewind src dst sig n · mmove dst ?? R))
(nop …)
partest1).
nth dst ? int (niltape ?) = midtape sig ls0 s (xs@cj::rs0) ∧
ci ≠ cj)).
-axiom daemon : ∀X:Prop.X.
-
lemma sem_match_step :
∀src,dst,sig,n.src ≠ dst → src < S n → dst < S n →
match_step src dst sig n ⊨
(acc_sem_if ? n … (sem_partest sig n (match_test src dst sig ?))
(sem_seq …
(sem_rewind ???? Hneq Hsrc Hdst)
- (sem_inject … dst (le_S_S_to_le … Hdst) (sem_move_r ? )))
- (sem_nop …)))
+ (sem_move_multi … R ?))
+ (sem_nop …))) /2/
[ #ta #tb #tc * lapply (refl ? (current ? (nth src ? ta (niltape ?))))
cases (current ? (nth src ? ta (niltape ?))) in ⊢ (???%→%);
[ #Hcurta_src #Hcomp #_ * #td * >Hcomp [| % %2 %]
lapply (Hte … (refl ??) … (refl ??) (refl ??)) -Hte
>change_vec_commute // >change_vec_change_vec
>change_vec_commute [|@sym_not_eq //] >change_vec_change_vec #Hte
- >Hte in Htb; * * #_ >nth_change_vec // #Htb1
- lapply (Htb1 … (refl ??)) -Htb1 #Htb1 #Htb2 %
- [ @(eq_vec … (niltape ?)) #i #Hi
- cases (true_or_false ((dst : DeqNat) == i)) #Hdsti
- [ <(\P Hdsti) >Htb1 >nth_change_vec // >Hmidta_dst
- >Hrs0 >reverse_reverse cases xs [|#r1 #rs1] %
- | <Htb2 [|@(\Pf Hdsti)] >nth_change_vec_neq [| @(\Pf Hdsti)]
- >Hrs0 >reverse_reverse >nth_change_vec_neq in ⊢ (???%);
- <Hrs <Hmidta_src [|@(\Pf Hdsti)] >change_vec_same % ]
+ >Hte in Htb; whd in ⊢ (%→?); #Htb >Htb %
+ [ >change_vec_change_vec >nth_change_vec //
+ >reverse_reverse <Hrs <Hmidta_src >change_vec_same <Hrs0 <Hmidta_dst
+ %
| >Hmidta_dst %{s'} % [%] #_
>Hrs0 %{xs} %{ci} %{rs''} %{ls0} %{cj} %{rs0'} % // % //
]
| lapply (\Pf Hss0) -Hss0 #Hss0 #Htc cut (tc = ta)
[@Htc % % @(not_to_not ??? Hss0) #H destruct (H) %]
-Htc #Htc destruct (Htc) #_ * #td * whd in ⊢ (%→?); * #_
- #Htd destruct (Htd) * #te * * #_ #Hte * * #_ #Htb1 #Htb2
+ #Htd destruct (Htd) * #te * * #_ #Hte whd in ⊢ (%→?); #Htb
#s1 #rs1 >Hmidta_src #H destruct (H)
lapply (Hte … Hmidta_src … Hmidta_dst) -Hte #Hte destruct (Hte) %
- [ @(eq_vec … (niltape ?)) #i #Hi
- cases (true_or_false ((dst : DeqNat) == i)) #Hdsti
- [ <(\P Hdsti) >(Htb1 … Hmidta_dst) >nth_change_vec // >Hmidta_dst
- cases rs0 [|#r2 #rs2] %
- | <Htb2 [|@(\Pf Hdsti)] >nth_change_vec_neq [| @(\Pf Hdsti)] % ]
+ [ >Htb %
| >Hs0 %{s0} % // #H destruct (H) @False_ind cases (Hss0) /2/ ]
]
]
λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
∀x,rs.
nth src ? int (niltape ?) = midtape sig [ ] x rs →
- (current sig (nth dst (tape sig) int (niltape sig)) = None ? → outt = int) ∧
+ (current sig (nth dst (tape sig) int (niltape sig)) = None ? →
+ right ? (nth dst (tape sig) int (niltape sig)) = [ ] → outt = int) ∧
(∀ls0,x0,rs0.
nth dst ? int (niltape ?) = midtape sig ls0 x0 rs0 →
(∃l,l1.x0::rs0 = l@x::rs@l1 ∧
lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
cases (current ? (nth dst ? ta (niltape ?))) in ⊢ (???%→?);
[#Hcurta_dst %
- [#_ whd in Htrue; >Hmidta_src in Htrue; #Htrue
- cases (Htrue ?? (refl ??)) -Htrue >Hcurta_dst
- (* dovremmo sapere che ta.dst è sul margine destro, da cui la move non
- ha effetto *) #_ cut (tc = ta) [@daemon] #Htc destruct (Htc) #_
+ [#Hcurta_dst #Hrightta_dst whd in Htrue; >Hmidta_src in Htrue; #Htrue
+ cases (Htrue ?? (refl ??)) -Htrue #Htc
+ cut (tc = ta)
+ [ >Htc whd in match (tape_move_mono ???); whd in match (tape_write ???);
+ <(change_vec_same … ta dst (niltape ?)) in ⊢ (???%);
+ lapply Hrightta_dst lapply Hcurta_dst -Hrightta_dst -Hcurta_dst
+ cases (nth dst ? ta (niltape ?))
+ [ #_ #_ %
+ | #r0 #rs0 #_ normalize in ⊢ (%→?); #H destruct (H)
+ | #l0 #ls0 #_ #_ %
+ | #ls #x0 #rs normalize in ⊢ (%→?); #H destruct (H) ] ]
+ -Htc #Htc destruct (Htc) #_
cases (IH … Hmidta_src) #Houtc #_ @Houtc //
|#ls0 #x0 #rs0 #Hmidta_dst >Hmidta_dst in Hcurta_dst;
normalize in ⊢ (%→?); #H destruct (H)
]
qed.
-definition Pre_match_m ≝
- λsrc,sig,n.λt: Vector (tape sig) (S n).
- ∃x,xs.
- nth src (tape sig) t (niltape sig) = midtape ? [] x xs.
-
+definition R_match_step_true_naive ≝
+ λsrc,dst,sig,n.λint,outt: Vector (tape sig) (S n).
+ |left ? (nth src ? outt (niltape ?))| +
+ |option_cons ? (current ? (nth dst ? outt (niltape ?))) (right ? (nth dst ? outt (niltape ?)))| <
+ |left ? (nth src ? int (niltape ?))| +
+ |option_cons ? (current ? (nth dst ? int (niltape ?))) (right ? (nth dst ? int (niltape ?)))|.
+
+lemma sem_match_step_termination :
+ ∀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_naive 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_rewind_strong ???? Hneq Hsrc Hdst)
+ (sem_move_multi … R ?))
+ (sem_nop …))) [/2/]
+[ #ta #tb #tc * lapply (refl ? (current ? (nth src ? ta (niltape ?))))
+ cases (current ? (nth src ? ta (niltape ?))) in ⊢ (???%→%);
+ [ #Hcurta_src #Hcomp #_ * #td * >Hcomp [| % %2 %]
+ whd in ⊢ (%→?); * whd in ⊢ (??%?→?);
+ >nth_current_chars >Hcurta_src normalize in ⊢ (%→?); #H destruct (H)
+ | #s #Hs lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
+ cases (current ? (nth dst ? ta (niltape ?))) in ⊢ (???%→%);
+ [ #Hcurta_dst #Hcomp #_ * #td * >Hcomp [| %2 %]
+ whd in ⊢ (%→?); * whd in ⊢ (??%?→?);
+ >nth_current_chars >nth_current_chars >Hs >Hcurta_dst
+ normalize in ⊢ (%→?); #H destruct (H)
+ | #s0 #Hs0
+ cases (current_to_midtape … Hs) #ls * #rs #Hmidta_src >Hmidta_src
+ cases (current_to_midtape … Hs0) #ls0 * #rs0 #Hmidta_dst >Hmidta_dst
+ cases (true_or_false (s == s0)) #Hss0
+ [ lapply (\P Hss0) -Hss0 #Hss0 destruct (Hss0)
+ #_ #Hcomp cases (Hcomp ????? (refl ??) (refl ??)) -Hcomp [ *
+ [ * #rs' * #_ #Hcurtc_dst * #td * whd in ⊢ (%→?); * whd in ⊢ (??%?→?);
+ >nth_current_chars >nth_current_chars >Hcurtc_dst
+ cases (current ? (nth src …))
+ [normalize in ⊢ (%→?); #H destruct (H)
+ | #x >nth_change_vec [|@Hdst] cases (reverse ? rs0)
+ [ normalize in ⊢ (%→?); #H destruct (H)
+ | #r1 #rs1 normalize in ⊢ (%→?); #H destruct (H) ] ]
+ | * #rs0' * #_ #Hcurtc_src * #td * whd in ⊢ (%→?); * whd in ⊢ (??%?→?);
+ >(?:nth src ? (current_chars ?? tc) (None ?) = None ?)
+ [|>nth_current_chars >Hcurtc_src >nth_change_vec_neq
+ [>nth_change_vec [cases (append ???) // | @Hsrc]
+ |@(not_to_not … Hneq) //
+ ]]
+ normalize in ⊢ (%→?); #H destruct (H) ]
+ | * #xs * #ci * #cj * #rs'' * #rs0' * * * #Hcicj #Hrs #Hrs0
+ #Htc * #td * * #Hmatch #Htd destruct (Htd) * #te * * *
+ >Htc >change_vec_commute [|//] >nth_change_vec [|//]
+ >change_vec_commute [|@sym_not_eq //] >nth_change_vec [|//]
+ cases (lists_length_split ? ls ls0) #lsa * #lsb * * #Hlen #Hlsalsb
+ destruct (Hlsalsb) *
+ [ #Hte #_ #_ <(reverse_reverse … ls) in Hte; <(reverse_reverse … lsa)
+ cut (|reverse ? lsa| = |reverse ? ls|) [ // ] #Hlen'
+ @(list_cases2 … Hlen')
+ [ #H1 #H2 >H1 >H2 -H1 -H2 normalize in match (reverse ? [ ]); #Hte #_
+ lapply (Hte … (refl ??) … (refl ??) (refl ??)) -Hte
+ >change_vec_commute [|//] >change_vec_change_vec
+ >change_vec_commute [|@sym_not_eq //] >change_vec_change_vec #Hte
+ >Hte whd in ⊢ (%→?); >change_vec_change_vec >nth_change_vec [|//]
+ >reverse_reverse #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta (midtape sig [ ] s0 (xs@ci::rs'')) src) (mk_tape sig (s0::lsb) (option_hd sig (xs@cj::rs0')) (tail sig (xs@cj::rs0'))) dst)
+ [ >Htb @eq_f3 // cases (xs@cj::rs0') // ]
+ -Htb #Htb >Htb whd >nth_change_vec [|//]
+ >nth_change_vec_neq [|@sym_not_eq //] >nth_change_vec [|//]
+ >right_mk_tape [|cases xs [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H)]
+ normalize in match (left ??);
+ >Hmidta_src >Hmidta_dst >current_mk_tape <opt_cons_tail_expand
+ whd in match (option_cons ???); >Hrs0
+ normalize in ⊢ (?(?%)%); //
+ | #hda #hdb #tla #tlb #H1 #H2 >H1 >H2
+ >reverse_cons >reverse_cons #Hte
+ lapply (Hte ci hdb (reverse ? xs@s0::reverse ? tlb) rs'' ?
+ lsb cj hda (reverse ? xs@s0::reverse ? tla) rs0' ??)
+ [ /2 by cons_injective_l, nil/
+ | >length_append >length_append @eq_f @(eq_f ?? S)
+ >H1 in Hlen'; >H2 whd in ⊢ (??%%→?); #Hlen'
+ >length_reverse >length_reverse destruct (Hlen') //
+ | /2 by refl, trans_eq/ ] -Hte
+ #Hte #_ whd in ⊢ (%→?); #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta
+ (mk_tape sig (hda::lsb) (option_hd ? (reverse sig (reverse sig xs@s0::reverse sig tla)@cj::rs0')) (tail ? (reverse sig (reverse sig xs@s0::reverse sig tla)@cj::rs0'))) dst)
+ (midtape ? [ ] hdb (reverse sig (reverse sig xs@s0::reverse sig tlb)@ci::rs'')) src)
+ [ >Htb >Hte >nth_change_vec // >change_vec_change_vec >change_vec_commute [|//]
+ >change_vec_change_vec >change_vec_commute [|@sym_not_eq //]
+ >change_vec_change_vec >change_vec_commute [|//]
+ @eq_f3 // cases (reverse sig (reverse sig xs@s0::reverse sig tla)@cj::rs0') // ]
+ -Htb #Htb >Htb whd
+ >nth_change_vec [|//] >nth_change_vec_neq [|//] >nth_change_vec [|//]
+ >right_mk_tape
+ [| cases (reverse sig (reverse sig xs@s0::reverse sig tla))
+ [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H) ]
+ >Hmidta_src >Hmidta_dst
+ whd in match (left ??); whd in match (left ??); whd in match (right ??);
+ >current_mk_tape <opt_cons_tail_expand whd in match (option_cons ???);
+ >Hrs0 >length_append whd in ⊢ (??(??%)); >length_append >length_reverse
+ >length_append >commutative_plus in match (|reverse ??| + ?);
+ whd in match (|?::?|); >length_reverse >length_reverse
+ <(length_reverse ? ls) <Hlen' >H1 normalize // ]
+ | #_ #Hte #_ <(reverse_reverse … ls0) in Hte; <(reverse_reverse … lsa)
+ cut (|reverse ? lsa| = |reverse ? ls0|) [ // ] #Hlen'
+ @(list_cases2 … Hlen')
+ [ #H1 #H2 >H1 >H2 normalize in match (reverse ? [ ]); #Hte
+ lapply (Hte … (refl ??) … (refl ??) (refl ??)) -Hte
+ >change_vec_change_vec >change_vec_commute [|@sym_not_eq //]
+ >change_vec_change_vec #Hte #_
+ >Hte whd in ⊢ (%→?); >nth_change_vec [|//] >reverse_reverse #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta (mk_tape ? [s0] (option_hd ? (xs@cj::rs0')) (tail ? (xs@cj::rs0'))) dst)
+ (midtape ? lsb s0 (xs@ci::rs'')) src)
+ [ >Htb >change_vec_change_vec >change_vec_commute [|//]
+ @eq_f3 // <Hrs0 cases rs0 // ]
+ -Htb #Htb >Htb whd >nth_change_vec [|//]
+ >nth_change_vec_neq [|//] >nth_change_vec [|//]
+ >right_mk_tape
+ [| cases xs [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H) ]
+ normalize in match (left ??);
+ >Hmidta_src >Hmidta_dst >current_mk_tape <opt_cons_tail_expand >Hrs0
+ >length_append normalize >length_append >length_append
+ <(reverse_reverse ? lsa) >H1 normalize //
+ | #hda #hdb #tla #tlb #H1 #H2 >H1 >H2
+ >reverse_cons >reverse_cons #Hte
+ lapply (Hte cj hdb (reverse ? xs@s0::reverse ? tlb) rs0' ?
+ lsb ci hda (reverse ? xs@s0::reverse ? tla) rs'' ??)
+ [ /2 by cons_injective_l, nil/
+ | >length_append >length_append @eq_f @(eq_f ?? S)
+ >H1 in Hlen'; >H2 whd in ⊢ (??%%→?); #Hlen'
+ >length_reverse >length_reverse destruct (Hlen') //
+ | /2 by refl, trans_eq/ ] -Hte
+ #Hte #_ whd in ⊢ (%→?); >Hte >nth_change_vec_neq [|//] >nth_change_vec [|//] #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta
+ (mk_tape sig [hdb] (option_hd ? (reverse sig (reverse sig xs@s0::reverse sig tlb)@cj::rs0')) (tail ? (reverse sig (reverse sig xs@s0::reverse sig tlb)@cj::rs0'))) dst)
+ (midtape ? lsb hda (reverse sig (reverse sig xs@s0::reverse sig tla)@ci::rs'')) src)
+ [ >Htb >change_vec_change_vec >change_vec_commute [|//]
+ >change_vec_change_vec >change_vec_commute [|@sym_not_eq //]
+ >change_vec_change_vec >change_vec_commute [|//]
+ @eq_f3 // cases (reverse sig (reverse sig xs@s0::reverse sig tlb)@cj::rs0') // ]
+ -Htb #Htb >Htb whd
+ >nth_change_vec [|//] >nth_change_vec_neq [|//] >nth_change_vec [|//]
+ >right_mk_tape
+ [| cases (reverse sig (reverse sig xs@s0::reverse sig tlb))
+ [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H) ]
+ >Hmidta_src >Hmidta_dst
+ whd in match (left ??); whd in match (left ??); whd in match (right ??);
+ >current_mk_tape <opt_cons_tail_expand
+ whd in match (option_cons ???);
+ >Hrs0 >length_append whd in ⊢ (??(??%)); >length_append >length_reverse
+ >length_append >commutative_plus in match (|reverse ??| + ?);
+ whd in match (|?::?|); >length_reverse >length_reverse
+ <(length_reverse ? lsa) >Hlen' >H2 >length_append
+ normalize //
+ ]
+ ]
+ ]
+ | lapply (\Pf Hss0) -Hss0 #Hss0 #Htc cut (tc = ta)
+ [@Htc % % @(not_to_not ??? Hss0) #H destruct (H) %]
+ -Htc #Htc destruct (Htc) #_ * #td * whd in ⊢ (%→?); * #_
+ #Htd destruct (Htd) * #te * * * * >Hmidta_src >Hmidta_dst
+ cases (lists_length_split ? ls ls0) #lsa * #lsb * * #Hlen #Hlsalsb
+ destruct (Hlsalsb)
+ [ <(reverse_reverse … ls) <(reverse_reverse … lsa)
+ cut (|reverse ? lsa| = |reverse ? ls|) [ // ] #Hlen'
+ @(list_cases2 … Hlen')
+ [ #H1 #H2 >H1 >H2 -H1 -H2 #_ #_ normalize in match (reverse ? [ ]); #Hte #_
+ lapply (Hte … (refl ??) … (refl ??)) -Hte #Hte destruct (Hte)
+ whd in ⊢ (%→?); >Hmidta_dst #Htb
+ cut (tb = change_vec ?? ta (mk_tape ? (s0::lsa@lsb) (option_hd ? rs0) (tail ? rs0)) dst)
+ [ >Htb cases rs0 // ]
+ -Htb #Htb >Htb whd >nth_change_vec [|//]
+ >nth_change_vec_neq [|@sym_not_eq //] >Hmidta_src >Hmidta_dst
+ >right_mk_tape
+ [| cases rs0 [ #_ %2 % | #x0 #xs0 normalize in ⊢ (??%?→?); #H destruct (H)] ]
+ normalize in match (left ??); normalize in match (right ??);
+ >Hmidta_src >Hmidta_dst >current_mk_tape <opt_cons_tail_expand
+ normalize //
+ | #hda #hdb #tla #tlb #H1 #H2 >H1 >H2
+ >reverse_cons >reverse_cons >associative_append #Hte
+ lapply (Hte ???? (refl ??) ? s0 ? (reverse ? tla) ?? (refl ??))
+ [ >length_reverse >length_reverse cut (|hda::tla| = |hdb::tlb|) //
+ normalize #H destruct (H) // ] #Hte #_ #_ #_
+ whd in ⊢ (%→?); >Hte >change_vec_change_vec >nth_change_vec // #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta
+ (mk_tape sig (hda::lsb) (option_hd ? (reverse sig (reverse sig tla)@s0::rs0)) (tail ? (reverse sig (reverse sig tla)@s0::rs0))) dst)
+ (midtape ? [ ] hdb (reverse sig (reverse sig tlb)@s::rs)) src)
+ [ >Htb >change_vec_commute [|//] @eq_f3 // cases (reverse sig (reverse sig tla)@s0::rs0) // ]
+ -Htb #Htb >Htb whd
+ >nth_change_vec [|//] >nth_change_vec_neq [|//] >nth_change_vec [|//]
+ >right_mk_tape
+ [| cases (reverse sig (reverse sig tla))
+ [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H) ]
+ >Hmidta_src >Hmidta_dst
+ whd in match (left ??); whd in match (left ??); whd in match (right ??);
+ >current_mk_tape <opt_cons_tail_expand >length_append
+ >length_reverse >length_reverse <(length_reverse ? ls) <Hlen'
+ >H1 normalize // ]
+ | #_ <(reverse_reverse … ls0) <(reverse_reverse … lsa)
+ cut (|reverse ? lsa| = |reverse ? ls0|) [ // ] #Hlen'
+ @(list_cases2 … Hlen')
+ [ #H1 #H2 >H1 >H2 normalize in match (reverse ? [ ]); #_ #_ #Hte
+ lapply (Hte … (refl ??) … (refl ??)) -Hte #Hte destruct (Hte)
+ whd in ⊢ (%→?); #Htb whd >Hmidta_dst
+ cut (tb = change_vec (tape sig) (S n) ta (mk_tape ? (s0::ls0) (option_hd ? rs0) (tail ? rs0)) dst)
+ [ >Htb >Hmidta_dst cases rs0 // ]
+ -Htb #Htb >Htb whd >nth_change_vec [|//]
+ >nth_change_vec_neq [|@sym_not_eq //] >Hmidta_src >Hmidta_dst
+ >current_mk_tape >right_mk_tape
+ [| cases rs0 [ #_ %2 % | #x0 #xs0 normalize in ⊢ (??%?→?); #H destruct (H) ]]
+ normalize in ⊢ (??%); <opt_cons_tail_expand
+ normalize //
+ | #hda #hdb #tla #tlb #H1 #H2 >H1 >H2
+ >reverse_cons >reverse_cons #Hte #_ #_
+ lapply (Hte s0 hdb (reverse ? tlb) rs0 ?
+ lsb s hda (reverse ? tla) rs ??)
+ [ /2 by cons_injective_l, nil/
+ | >length_reverse >length_reverse cut (|hda::tla| = |hdb::tlb|) //
+ normalize #H destruct (H) //
+ | /2 by refl, trans_eq/ ] -Hte
+ #Hte whd in ⊢ (%→?); >Hte >nth_change_vec_neq [|//] >nth_change_vec [|//] #Htb
+ cut (tb = change_vec ?? (change_vec (tape sig) (S n) ta
+ (mk_tape sig [hdb] (option_hd ? (reverse sig (reverse sig tlb)@s0::rs0)) (tail ? (reverse sig (reverse sig tlb)@s0::rs0))) dst)
+ (midtape ? lsb hda (reverse sig (reverse sig tla)@s::rs)) src)
+ [ >Htb >change_vec_commute [|//] >change_vec_change_vec
+ @eq_f3 // cases (reverse sig (reverse sig tlb)@s0::rs0) // ]
+ -Htb #Htb >Htb whd
+ >nth_change_vec [|//] >nth_change_vec_neq [|//] >nth_change_vec [|//]
+ >right_mk_tape
+ [| cases (reverse ? (reverse ? tlb)) [|#x0 #xs0] normalize in ⊢ (??%?→?); #H destruct (H) ]
+ >Hmidta_src >Hmidta_dst
+ whd in match (left ??); whd in match (left ??); whd in match (right ??);
+ >current_mk_tape <opt_cons_tail_expand >length_append
+ normalize in ⊢ (??%); >length_append >reverse_reverse
+ <(length_reverse ? lsa) >Hlen' >H2 normalize //
+ ]
+ ]
+ ]
+ ]
+ ]
+| #ta #tb #tc * #Hcomp1 #Hcomp2 * #td * * #Htest #Htd destruct (Htd)
+ whd in ⊢ (%→?); #Htb destruct (Htb) #ls #x #xs #Hta_src
+ lapply (refl ? (current ? (nth dst ? ta (niltape ?))))
+ cases (current ? (nth dst ? ta (niltape ?))) in ⊢ (???%→?);
+ [ #Hcurta_dst % % % // @Hcomp1 %2 //
+ | #x0 #Hcurta_dst cases (current_to_midtape … Hcurta_dst) -Hcurta_dst
+ #ls0 * #rs0 #Hta_dst cases (true_or_false (x == x0)) #Hxx0
+ [ lapply (\P Hxx0) -Hxx0 #Hxx0 destruct (Hxx0)
+ | >(?:tc=ta) in Htest;
+ [|@Hcomp1 % % >Hta_src >Hta_dst @(not_to_not ??? (\Pf Hxx0)) normalize
+ #Hxx0' destruct (Hxx0') % ]
+ whd in ⊢ (??%?→?);
+ >nth_current_chars >Hta_src >nth_current_chars >Hta_dst
+ whd in ⊢ (??%?→?); #Hfalse destruct (Hfalse) ] -Hcomp1
+ cases (Hcomp2 … Hta_src Hta_dst) [ *
+ [ * #rs' * #Hxs #Hcurtc % %2 %{ls0} %{rs0} %{rs'} %
+ [ % // | >Hcurtc % ]
+ | * #rs0' * #Hxs #Htc %2 >Htc %{ls0} %{rs0'} % // ]
+ | * #xs0 * #ci * #cj * #rs' * #rs0' * * *
+ #Hci #Hxs #Hrs0 #Htc @False_ind
+ whd in Htest:(??%?);
+ >(?:nth src ? (current_chars ?? tc) (None ?) = Some ? ci) in Htest;
+ [|>nth_current_chars >Htc >nth_change_vec_neq [|@(not_to_not … Hneq) //]
+ >nth_change_vec //]
+ >(?:nth dst ? (current_chars ?? tc) (None ?) = Some ? cj)
+ [|>nth_current_chars >Htc >nth_change_vec //]
+ normalize #H destruct (H) ] ] ]
+qed.
+
+(* lemma WF_to_WF_f : ∀A,B,R,f,b. WF A R (f b) → WF B (λx,y.R (f x) (f y)) b. *)
+let rec WF_to_WF_f A B R f b (Hwf: WF A R (f b)) on Hwf: WF B (λx,y.R (f x) (f y)) b ≝
+ match Hwf return (λa0,r.f b = a0 → WF B (λx,y:B. R (f x) (f y)) b) with
+ [ wf a Hwfa ⇒ λHeq.? ] (refl ??).
+% #b1 #HRb @WF_to_WF_f @Hwfa <Heq @HRb
+qed.
+
+lemma lt_WF : ∀n.WF ? lt n.
+#n @(nat_elim1 n) -n #n #IH % @IH
+qed.
+
lemma terminate_match_m :
∀src,dst,sig,n,t.
src ≠ dst → src < S n → dst < S n →
- Pre_match_m src sig n t →
match_m src dst sig n ↓ t.
-#src #dst #sig #n #t #Hneq #Hsrc #Hdst * #start * #xs
-#Hmid_src
-@(terminate_while … (sem_match_step src dst sig n 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 #_ * #s0 * normalize in ⊢ (%→?); #H destruct (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 ⊢ (%→?);
- * #s0 * #H destruct (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 ⊢ (%→?);
- * #s0 * #H destruct (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
- >change_vec_change_vec #Ht1 #_ % #t2 whd in ⊢ (%→?);
- >Ht1 >nth_change_vec_neq [|@sym_not_eq //] >Hmid_src #HR
- cases (HR ?? (refl ??)) -HR #_
- >nth_change_vec // * #s1 * normalize in ⊢ (%→?); #H destruct (H)
- |#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 >change_vec_change_vec
- >nth_change_vec // >Hmid_dst whd in match (tape_move_mono ???); #Ht1
- * #s0 * whd in ⊢ (??%?→?); #H destruct (H) #_ >Ht1
- lapply (IH t1 ? (s0::ls) r0 ?)
- [ >Ht1 >nth_change_vec //
- | >Ht1 >nth_change_vec_neq [|@sym_not_eq //] @Hmid_src
- | >Ht1 >nth_change_vec // ]
- ]
-]
+#src #dst #sig #n #ta #Hneq #Hsrc #Hdst
+@(terminate_while … (sem_match_step_termination src dst sig n Hneq Hsrc Hdst)) //
+letin f ≝ (λt0:Vector (tape sig) (S n).|left ? (nth src (tape ?) t0 (niltape ?))|
+ +|option_cons ? (current ? (nth dst (tape ?) t0 (niltape ?)))
+ (right ? (nth dst (tape ?) t0 (niltape ?)))|)
+change with (λx,y.f x < f y) in ⊢ (??%?); @WF_to_WF_f @lt_WF
+qed.
+
+lemma sem_match_m : ∀src,dst,sig,n.
+src ≠ dst → src < S n → dst < S n →
+ match_m src dst sig n \vDash R_match_m src dst sig n.
+#src #dst #sig #n #Hneq #Hsrc #Hdst @WRealize_to_Realize [/2/| @wsem_match_m // ]
qed.
\ No newline at end of file