if f a then 〈acc,a::tl〉 else split_on A tl f (a::acc)
].
-lemma split_on_spec: ∀A,l,f,acc,res1,res2.
+lemma split_on_spec: ∀A:DeqSet.∀l,f,acc,res1,res2.
split_on A l f acc = 〈res1,res2〉 →
(∃l1. res1 = l1@acc ∧
reverse ? l1@res2 = l ∧
- ∀x. mem ? x l1 → f x = false) ∧
+ ∀x. memb ? x l1 =true → f x = false) ∧
∀a,tl. res2 = a::tl → f a = true.
#A #l #f elim l
[#acc #res1 #res2 normalize in ⊢ (%→?); #H destruct %
- [@(ex_intro … []) % normalize [% % | #x @False_ind]
+ [@(ex_intro … []) % normalize [% % | #x #H destruct]
|#a #tl #H destruct
]
|#a #tl #Hind #acc #res1 #res2 normalize in ⊢ (%→?);
cases (true_or_false (f a)) #Hfa >Hfa normalize in ⊢ (%→?);
#H destruct
- [% [@(ex_intro … []) % normalize [% % | #x @False_ind]
+ [% [@(ex_intro … []) % normalize [% % | #x #H destruct]
|#a1 #tl1 #H destruct (H) //]
|cases (Hind (a::acc) res1 res2 H) * #l1 * *
#Hres1 #Htl #Hfalse #Htrue % [2:@Htrue] @(ex_intro … (l1@[a])) %
[% [>associative_append @Hres1 | >reverse_append <Htl % ]
- |#x #Hmemx cases (mem_append ???? Hmemx)
- [@Hfalse | normalize * [#H >H //| @False_ind]
+ |#x #Hmemx cases (memb_append ???? Hmemx)
+ [@Hfalse | #H >(memb_single … H) //]
]
]
]
axiom mem_reverse: ∀A,l,x. mem A x (reverse ? l) → mem A x l.
-lemma split_on_spec_ex: ∀A,l,f.∃l1,l2.
- l1@l2 = l ∧ (∀x:A. mem ? x l1 → f x = false) ∧
+lemma split_on_spec_ex: ∀A:DeqSet.∀l,f.∃l1,l2.
+ l1@l2 = l ∧ (∀x:A. memb ? x l1 = true → f x = false) ∧
∀a,tl. l2 = a::tl → f a = true.
#A #l #f @(ex_intro … (reverse … (\fst (split_on A l f []))))
@(ex_intro … (\snd (split_on A l f [])))
cases (split_on_spec A l f [ ] ?? (eq_pair_fst_snd …)) * #l1 * *
>append_nil #Hl1 >Hl1 #Hl #Hfalse #Htrue %
- [% [@Hl|#x #memx @Hfalse @mem_reverse //] | @Htrue]
+ [% [@Hl|#x #memx @Hfalse <(reverse_reverse … l1) @memb_reverse //] | @Htrue]
qed.
(* versione esistenziale *)
>reverse_append >reverse_append >associative_append
>associative_append %
]
- |lapply Hbs1 lapply Hbs2 lapply Hrs -Hbs1 -Hbs2 -Hrs
+ |lapply Hbs1 lapply Hb0s1 lapply Hbs2 lapply Hb0s2 lapply Hrs
+ -Hbs1 -Hb0s1 -Hbs2 -Hb0s2 -Hrs
@(list_cases2 … Hlen)
- [#Hrs #_ #_ >associative_append >associative_append #Htapeb #_
+ [#Hrs #_ #_ #_ #_ >associative_append >associative_append #Htapeb #_
lapply (Htapeb … (\P eqbb0) … (refl …) (refl …)) -Htapeb #Htapeb
cases (IH … Htapeb) -IH * #Hout #_ #_ %1 %
[>(\P eqbb0) %
|>(Hout grid (refl …) (refl …)) @eq_f
normalize >associative_append %
]
- |* #a1 #ba1 * #a2 #ba2 #tl1 #tl2 #HlenS #Hrs #Hbs1 #Hbs2
- cut (ba1 = false) [@(Hbs1 〈a1,ba1〉) @memb_hd] #Hba1 >Hba1
+ |* #a1 #ba1 * #a2 #ba2 #tl1 #tl2 #HlenS #Hrs #Hb0s2 #Hbs2 #Hb0s1 #Hbs1
+ cut (ba1 = false) [@(Hbs2 〈a1,ba1〉) @memb_hd] #Hba1 >Hba1
>associative_append >associative_append #Htapeb #_
lapply (Htapeb … (\P eqbb0) … (refl …) (refl …)) -Htapeb #Htapeb
cases (IH … Htapeb) -IH * #_ #_
+ cut (ba2=false) [@(Hb0s2 〈a2,ba2〉) @memb_hd] #Hba2 >Hba2
#IH cases(IH a1 a2 ?? (l1@[〈b0,false〉]) l2 HlenS ????? (refl …) ??)
- [
-
-
-(*
- cut (∃a,l1'.〈a,false〉::l1'=((bs@[〈grid,false〉])@l1)@[〈b0,false〉])
- [generalize in match Hbs2; cases bs
- [#_ @(ex_intro … grid) @(ex_intro … (l1@[〈b0,false〉]))
- >associative_append %
- |* #bsc #bsb #bstl #Hbs2 @(ex_intro … bsc)
- @(ex_intro … (((bstl@[〈grid,false〉])@l1)@[〈b0,false〉]))
- normalize @eq_f2 [2:%] @eq_f @sym_eq @(Hbs2 〈bsc,bsb〉) @memb_hd
- ]
- ]
- * #a * #l1' #H2
- cut (∃a0,b1,l2'.b0s@〈comma,false〉::l2=〈a0,b1〉::l2')
- [cases b0s
- [@(ex_intro … comma) @(ex_intro … false) @(ex_intro … l2) %
- |* #bsc #bsb #bstl @(ex_intro … bsc) @(ex_intro … bsb)
- @(ex_intro … (bstl@〈comma,false〉::l2)) %
- ]
- ] *)
- * #a0 * #b1 * #l2' #H3
- lapply (Htapeb … (\P eqbb0) a a0 b1 l1' l2' H2 H3) -Htapeb #Htapeb
- cases (IH … Htapeb) -IH *
-
-
- [2: * >Hc' #Hfalse @False_ind destruct ] * #_
- @(list_cases2 … Hlen)
- [ #Hbs #Hb0s generalize in match Hrs; >Hbs in ⊢ (%→?); >Hb0s in ⊢ (%→?);
- -Hrs #Hrs normalize in Hrs; #Hleft cases (Hleft ????? Hrs ?) -Hleft
- [ * #Heqb #Htapeb cases (IH … Htapeb) -IH * #IH #_ #_
- % %
- [ >Heqb >Hbs >Hb0s %
- | >Hbs >Hb0s @IH %
- ]
- |* #Hneqb #Htapeb %2
- @(ex_intro … [ ]) @(ex_intro … b)
- @(ex_intro … b0) @(ex_intro … [ ])
- @(ex_intro … [ ]) %
- [ % [ % [@sym_not_eq //| >Hbs %] | >Hb0s %]
- | cases (IH … Htapeb) -IH * #_ #IH #_ >(IH ? (refl ??))
- @Htapeb
- ]
- | @Hl1 ]
- | * #b' #bitb' * #b0' #bitb0' #bs' #b0s' #Hbs #Hb0s
- generalize in match Hrs; >Hbs in ⊢ (%→?); >Hb0s in ⊢ (%→?);
- cut (bit_or_null b' = true ∧ bit_or_null b0' = true ∧
- bitb' = false ∧ bitb0' = false)
- [ % [ % [ % [ >Hbs in Hbs1; #Hbs1 @(Hbs1 〈b',bitb'〉) @memb_hd
- | >Hb0s in Hb0s1; #Hb0s1 @(Hb0s1 〈b0',bitb0'〉) @memb_hd ]
- | >Hbs in Hbs2; #Hbs2 @(Hbs2 〈b',bitb'〉) @memb_hd ]
- | >Hb0s in Hb0s2; #Hb0s2 @(Hb0s2 〈b0',bitb0'〉) @memb_hd ]
- | * * * #Ha #Hb #Hc #Hd >Hc >Hd
- #Hrs #Hleft
- cases (Hleft b' (bs'@〈grid,false〉::l1) b0 b0'
- (b0s'@〈comma,false〉::l2) ??) -Hleft
- [ 3: >Hrs normalize @eq_f >associative_append %
- | * #Hb0 #Htapeb cases (IH …Htapeb) -IH * #_ #_ #IH
- cases (IH b' b0' bs' b0s' (l1@[〈b0,false〉]) l2 ??????? Ha ?) -IH
- [ * #Heq #Houtc % %
- [ >Hb0 @eq_f >Hbs in Heq; >Hb0s in ⊢ (%→?); #Heq
- destruct (Heq) >Hb0s >Hc >Hd %
- | >Houtc >Hbs >Hb0s >Hc >Hd >reverse_cons >associative_append
- >associative_append %
+ [3:#x #memx @Hbs1 @memb_cons @memx
+ |4:#x #memx @Hb0s1 @memb_cons @memx
+ |5:#x #memx @Hbs2 @memb_cons @memx
+ |6:#x #memx @Hb0s2 @memb_cons @memx
+ |7:#x #memx cases (memb_append …memx) -memx #memx
+ [@Hl1 @memx | >(memb_single … memx) %]
+ |8:@(Hbs1 〈a1,ba1〉) @memb_hd
+ |9: >associative_append >associative_append %
+ |-IH -Hbs1 -Hb0s1 -Hbs2 -Hrs *
+ #Ha1a2 #Houtc %1 %
+ [>(\P eqbb0) @eq_f destruct (Ha1a2) %
+ |>Houtc @eq_f3
+ [>reverse_cons >associative_append %
+ |%
+ |>associative_append %
+ ]
]
- | * #la * #c' * #d' * #lb * #lc * * * #H1 #H2 #H3 #H4 %2
- @(ex_intro … (〈b,false〉::la)) @(ex_intro … c') @(ex_intro … d')
- @(ex_intro … lb) @(ex_intro … lc)
- % [ % [ % // >Hbs >Hc >H2 % | >Hb0s >Hd >H3 >Hb0 % ]
- | >H4 >Hbs >Hb0s >Hc >Hd >Hb0 >reverse_append
- >reverse_cons >reverse_cons
- >associative_append >associative_append
- >associative_append >associative_append %
+ |-IH -Hbs1 -Hb0s1 -Hbs2 -Hrs *
+ #la * #c' * #d' * #lb * #lc * * *
+ #Hcd #H1 #H2 #Houtc %2
+ @(ex_intro … (〈b,false〉::la)) @(ex_intro … c') @(ex_intro … d')
+ @(ex_intro … lb) @(ex_intro … lc) %
+ [%[%[@Hcd | >H1 %] |>(\P eqbb0) >Hba2 >H2 %]
+ |>Houtc @eq_f3
+ [>(\P eqbb0) >reverse_append >reverse_cons
+ >reverse_cons >associative_append >associative_append
+ >associative_append >associative_append %
+ |%
+ |%
]
- | generalize in match Hlen; >Hbs >Hb0s
- normalize #Hlen destruct (Hlen) @e0
- | #c0 #Hc0 @Hbs1 >Hbs @memb_cons //
- | #c0 #Hc0 @Hb0s1 >Hb0s @memb_cons //
- | #c0 #Hc0 @Hbs2 >Hbs @memb_cons //
- | #c0 #Hc0 @Hb0s2 >Hb0s @memb_cons //
- | #c0 #Hc0 cases (memb_append … Hc0)
- [ @Hl1 | #Hc0' >(memb_single … Hc0') % ]
- | %
- | >associative_append >associative_append % ]
- | * #Hneq #Htapeb %2
- @(ex_intro … []) @(ex_intro … b) @(ex_intro … b0)
- @(ex_intro … bs) @(ex_intro … b0s) %
- [ % // % // @sym_not_eq //
- | >Hbs >Hb0s >Hc >Hd >reverse_cons >associative_append
- >reverse_append in Htapeb; >reverse_cons
- >associative_append >associative_append
- #Htapeb <Htapeb
- cases (IH … Htapeb) -Htapeb -IH * #_ #IH #_ @(IH ? (refl ??))
- ]
- | #c1 #Hc1 cases (memb_append … Hc1) #Hyp
- [ @Hbs2 >Hbs @memb_cons @Hyp
- | cases (orb_true_l … Hyp)
- [ #Hyp2 >(\P Hyp2) %
- | @Hl1
- ]
- ]
- ]
-]]]]]
-qed.
+ ]
+ ]
+ ]
+ ]
+ ]
+ ]
+ ]
+]
+qed.
+
+lemma WF_cst_niltape:
+ WF ? (inv ? R_comp_step_true) (niltape (FinProd FSUnialpha FinBool)).
+@wf #t1 whd in ⊢ (%→?); * #ls * #c * #rs * #H destruct
+qed.
+
+lemma WF_cst_rightof:
+ ∀a,ls. WF ? (inv ? R_comp_step_true) (rightof (FinProd FSUnialpha FinBool) a ls).
+#a #ls @wf #t1 whd in ⊢ (%→?); * #ls * #c * #rs * #H destruct
+qed.
+
+lemma WF_cst_leftof:
+ ∀a,ls. WF ? (inv ? R_comp_step_true) (leftof (FinProd FSUnialpha FinBool) a ls).
+#a #ls @wf #t1 whd in ⊢ (%→?); * #ls * #c * #rs * #H destruct
+qed.
+
+lemma WF_cst_midtape_false:
+ ∀ls,c,rs. WF ? (inv ? R_comp_step_true)
+ (midtape (FinProd … FSUnialpha FinBool) ls 〈c,false〉 rs).
+#ls #c #rs @wf #t1 whd in ⊢ (%→?); * #ls' * #c' * #rs' * #H destruct
+qed.
+
+(* da spostare *)
+lemma not_nil_to_exists:∀A.∀l: list A. l ≠ [ ] →
+ ∃a,tl. a::tl = l.
+ #A * [* #H @False_ind @H // | #a #tl #_ @(ex_intro … a) @(ex_intro … tl) //]
+ qed.
+
+axiom daemon : ∀P:Prop.P.
+
+lemma terminate_compare:
+ ∀t. Terminate ? compare t.
+#t @(terminate_while … sem_comp_step) [%]
+cases t // #ls * #c * //
+#rs lapply ls; lapply c; -ls -c
+(* we cannot proceed by structural induction on the right tape,
+ since compare moves the marks! *)
+elim rs
+ [#c #ls @wf #t1 whd in ⊢ (%→?); * #ls0 * #c0 * #rs0 * #Hmid destruct (Hmid)
+ * * #H1 #H2 #_ cases (true_or_false (bit_or_null c0)) #Hc0
+ [>(H2 Hc0 … (refl …)) // #x whd in ⊢ ((??%?)→?); #Hdes destruct
+ |>(H1 Hc0) //
+ ]
+ |#a #rs' #Hind #c #ls @wf #t1 whd in ⊢ (%→?); * #ls0 * #c0 * #rs0 * #Hmid destruct (Hmid)
+ * * #H1 #H2 #H3 cases (true_or_false (bit_or_null c0)) #Hc0
+ [-H1 cases (split_on_spec_ex ? (a::rs') (is_marked ?)) #rs1 * #rs2
+ cases rs2
+ [(* no marks in right tape *)
+ * * >append_nil #H >H -H #Hmarks #_
+ cases (not_nil_to_exists ? (reverse (FSUnialpha×bool) (〈c0,true〉::a::rs')) ?)
+ [2: % >reverse_cons #H cases (nil_to_nil … H) #_ #H1 destruct]
+ #a0 * #tl #H4 >(H2 Hc0 Hmarks a0 tl H4) //
+ |(* the first marked element is a0 *)
+ * #a0 #a0b #rs3 * * #H4 #H5 #H6 lapply (H3 ? a0 rs3 … Hc0 H5 ?)
+ [<H4 @eq_f @eq_f2 [@eq_f @(H6 〈a0,a0b〉 … (refl …)) | %]
+ |cases (true_or_false (c0==a0)) #eqc0a0 (* comparing a0 with c0 *)
+ [* * (* we check if we have elements at the right of a0 *) cases rs3
+ [#Ht1 #_ #_ >(Ht1 (\P eqc0a0) (refl …)) //
+ |(* a1 will be marked *)
+ cases (not_nil_to_exists ? (rs1@[〈a0,false〉]) ?)
+ [2: % #H cases (nil_to_nil … H) #_ #H1 destruct]
+ * #a2 #a2b * #tl2 #H7 * #a1 #a1b #rs4 #_ #Ht1 #_
+ cut (a2b =false) [@daemon] #Ha2b >Ha2b in H7; #H7
+ >(Ht1 (\P eqc0a0) … H7 (refl …))
+ cut (rs' = tl2@〈a1,true〉::rs4)
+ cut (a0b=false) [@(H6 〈a0,a0b〉)
+
+ |>(H1 Hc0) //
+ ]
+qed.
axiom sem_compare : Realize ? compare R_compare.