1 include "tutorial/chapter7.ma".
3 definition lo ≝ λS:DeqSet.λa,b:pre S.〈\fst a + \fst b,\snd a ∨ \snd b〉.
4 notation "a ⊕ b" left associative with precedence 60 for @{'oplus $a $b}.
5 interpretation "oplus" 'oplus a b = (lo ? a b).
7 lemma lo_def: ∀S.∀i1,i2:pitem S.∀b1,b2. 〈i1,b1〉⊕〈i2,b2〉=〈i1+i2,b1∨b2〉.
10 definition pre_concat_r ≝ λS:DeqSet.λi:pitem S.λe:pre S.
11 match e with [ mk_Prod i1 b ⇒ 〈i · i1, b〉].
13 notation "i ◃ e" left associative with precedence 60 for @{'lhd $i $e}.
14 interpretation "pre_concat_r" 'lhd i e = (pre_concat_r ? i e).
16 lemma eq_to_ex_eq: ∀S.∀A,B:word S → Prop.
18 #S #A #B #H >H /2/ qed.
20 lemma sem_pre_concat_r : ∀S,i.∀e:pre S.
21 \sem{i ◃ e} =1 \sem{i} · \sem{|\fst e|} ∪ \sem{e}.
22 #S #i * #i1 #b1 cases b1 [2: @eq_to_ex_eq //]
23 >sem_pre_true >sem_cat >sem_pre_true /2/
26 definition pre_concat_l ≝ λS:DeqSet.λbcast:∀S:DeqSet.pitem S → pre S.λe1:pre S.λi2:pitem S.
28 [ mk_Prod i1 b1 ⇒ match b1 with
29 [ true ⇒ (i1 ◃ (bcast ? i2))
30 | false ⇒ 〈i1 · i2,false〉
34 notation "a ▹ b" left associative with precedence 60 for @{'tril eclose $a $b}.
35 interpretation "item-pre concat" 'tril op a b = (pre_concat_l ? op a b).
37 notation "•" non associative with precedence 60 for @{eclose ?}.
39 let rec eclose (S: DeqSet) (i: pitem S) on i : pre S ≝
43 | ps x ⇒ 〈 `.x, false〉
44 | pp x ⇒ 〈 `.x, false 〉
45 | po i1 i2 ⇒ •i1 ⊕ •i2
47 | pk i ⇒ 〈(\fst (•i))^*,true〉].
49 notation "• x" non associative with precedence 60 for @{'eclose $x}.
50 interpretation "eclose" 'eclose x = (eclose ? x).
52 lemma eclose_plus: ∀S:DeqSet.∀i1,i2:pitem S.
53 •(i1 + i2) = •i1 ⊕ •i2.
56 lemma eclose_dot: ∀S:DeqSet.∀i1,i2:pitem S.
57 •(i1 · i2) = •i1 ▹ i2.
60 lemma eclose_star: ∀S:DeqSet.∀i:pitem S.
61 •i^* = 〈(\fst(•i))^*,true〉.
64 definition lift ≝ λS.λf:pitem S →pre S.λe:pre S.
66 [ mk_Prod i b ⇒ 〈\fst (f i), \snd (f i) ∨ b〉].
68 definition preclose ≝ λS. lift S (eclose S).
69 interpretation "preclose" 'eclose x = (preclose ? x).
72 lemma sem_oplus: ∀S:DeqSet.∀e1,e2:pre S.
73 \sem{e1 ⊕ e2} =1 \sem{e1} ∪ \sem{e2}.
74 #S * #i1 #b1 * #i2 #b2 #w %
75 [cases b1 cases b2 normalize /2/ * /3/ * /3/
76 |cases b1 cases b2 normalize /2/ * /3/ * /3/
82 〈i1,true〉 ▹ i2 = i1 ◃ (•i2).
87 〈i1,true〉 ▹ i2 = 〈i1 · \fst (•i2), \snd (•i2)〉.
88 #S #i1 #i2 normalize cases (•i2) // qed.
92 〈i1,false〉 ▹ i2 = 〈i1 · i2, false〉.
95 lemma LcatE : ∀S.∀e1,e2:pitem S.
96 \sem{e1 · e2} = \sem{e1} · \sem{|e2|} ∪ \sem{e2}.
99 lemma erase_bull : ∀S.∀i:pitem S. |\fst (•i)| = |i|.
101 [ #i1 #i2 #IH1 #IH2 >erase_dot <IH1 >eclose_dot
102 cases (•i1) #i11 #b1 cases b1 // <IH2 >odot_true_bis //
103 | #i1 #i2 #IH1 #IH2 >eclose_plus >(erase_plus … i1) <IH1 <IH2
104 cases (•i1) #i11 #b1 cases (•i2) #i21 #b2 //
105 | #i #IH >eclose_star >(erase_star … i) <IH cases (•i) //
110 lemma sem_eclose_star: ∀S:DeqSet.∀i:pitem S.
111 \sem{〈i^*,true〉} =1 \sem{〈i,false〉}·\sem{|i|}^* ∪ {ϵ}.
115 (* theorem 16: 1 → 3 *)
116 lemma odot_dot_aux : ∀S.∀e1:pre S.∀i2:pitem S.
117 \sem{•i2} =1 \sem{i2} ∪ \sem{|i2|} →
118 \sem{e1 ▹ i2} =1 \sem{e1} · \sem{|i2|} ∪ \sem{i2}.
119 #S * #i1 #b1 #i2 cases b1
120 [2:#th >odot_false >sem_pre_false >sem_pre_false >sem_cat /2/
121 |#H >odot_true >sem_pre_true @(eqP_trans … (sem_pre_concat_r …))
122 >erase_bull @eqP_trans [|@(eqP_union_l … H)]
123 @eqP_trans [|@eqP_union_l[|@union_comm ]]
124 @eqP_trans [|@eqP_sym @union_assoc ] /3/
128 lemma minus_eps_pre_aux: ∀S.∀e:pre S.∀i:pitem S.∀A.
129 \sem{e} =1 \sem{i} ∪ A → \sem{\fst e} =1 \sem{i} ∪ (A - {[ ]}).
131 @eqP_trans [|@minus_eps_pre]
132 @eqP_trans [||@eqP_union_r [|@eqP_sym @minus_eps_item]]
133 @eqP_trans [||@distribute_substract]
138 theorem sem_bull: ∀S:DeqSet. ∀i:pitem S. \sem{•i} =1 \sem{i} ∪ \sem{|i|}.
140 [#w normalize % [/2/ | * //]
142 |#x normalize #w % [ /2/ | * [@False_ind | //]]
143 |#x normalize #w % [ /2/ | * // ]
144 |#i1 #i2 #IH1 #IH2 >eclose_dot
145 @eqP_trans [|@odot_dot_aux //] >sem_cat
148 [|@eqP_trans [|@(cat_ext_l … IH1)] @distr_cat_r]]
149 @eqP_trans [|@union_assoc]
150 @eqP_trans [||@eqP_sym @union_assoc]
152 |#i1 #i2 #IH1 #IH2 >eclose_plus
153 @eqP_trans [|@sem_oplus] >sem_plus >erase_plus
154 @eqP_trans [|@(eqP_union_l … IH2)]
155 @eqP_trans [|@eqP_sym @union_assoc]
156 @eqP_trans [||@union_assoc] @eqP_union_r
157 @eqP_trans [||@eqP_sym @union_assoc]
158 @eqP_trans [||@eqP_union_l [|@union_comm]]
159 @eqP_trans [||@union_assoc] /2/
160 |#i #H >sem_pre_true >sem_star >erase_bull >sem_star
161 @eqP_trans [|@eqP_union_r [|@cat_ext_l [|@minus_eps_pre_aux //]]]
162 @eqP_trans [|@eqP_union_r [|@distr_cat_r]]
163 @eqP_trans [|@union_assoc] @eqP_union_l >erase_star
164 @eqP_sym @star_fix_eps
169 let rec blank (S: DeqSet) (i: re S) on i :pitem S ≝
174 | o e1 e2 ⇒ (blank S e1) + (blank S e2)
175 | c e1 e2 ⇒ (blank S e1) · (blank S e2)
176 | k e ⇒ (blank S e)^* ].
178 lemma forget_blank: ∀S.∀e:re S.|blank S e| = e.
179 #S #e elim e normalize //
182 lemma sem_blank: ∀S.∀e:re S.\sem{blank S e} =1 ∅.
186 |#e1 #e2 #Hind1 #Hind2 >sem_cat
187 @eqP_trans [||@(union_empty_r … ∅)]
188 @eqP_trans [|@eqP_union_l[|@Hind2]] @eqP_union_r
189 @eqP_trans [||@(cat_empty_l … ?)] @cat_ext_l @Hind1
190 |#e1 #e2 #Hind1 #Hind2 >sem_plus
191 @eqP_trans [||@(union_empty_r … ∅)]
192 @eqP_trans [|@eqP_union_l[|@Hind2]] @eqP_union_r @Hind1
194 @eqP_trans [||@(cat_empty_l … ?)] @cat_ext_l @Hind
198 theorem re_embedding: ∀S.∀e:re S.
199 \sem{•(blank S e)} =1 \sem{e}.
200 #S #e @eqP_trans [|@sem_bull] >forget_blank
201 @eqP_trans [|@eqP_union_r [|@sem_blank]]
202 @eqP_trans [|@union_comm] @union_empty_r.
205 (* lefted operations *)
206 definition lifted_cat ≝ λS:DeqSet.λe:pre S.
207 lift S (pre_concat_l S eclose e).
209 notation "e1 ⊙ e2" left associative with precedence 70 for @{'odot $e1 $e2}.
211 interpretation "lifted cat" 'odot e1 e2 = (lifted_cat ? e1 e2).
213 lemma odot_true_b : ∀S.∀i1,i2:pitem S.∀b.
214 〈i1,true〉 ⊙ 〈i2,b〉 = 〈i1 · (\fst (•i2)),\snd (•i2) ∨ b〉.
215 #S #i1 #i2 #b normalize in ⊢ (??%?); cases (•i2) //
218 lemma odot_false_b : ∀S.∀i1,i2:pitem S.∀b.
219 〈i1,false〉 ⊙ 〈i2,b〉 = 〈i1 · i2 ,b〉.
223 lemma erase_odot:∀S.∀e1,e2:pre S.
224 |\fst (e1 ⊙ e2)| = |\fst e1| · (|\fst e2|).
225 #S * #i1 * * #i2 #b2 // >odot_true_b >erase_dot //
228 definition lk ≝ λS:DeqSet.λe:pre S.
232 [true ⇒ 〈(\fst (eclose ? i1))^*, true〉
233 |false ⇒ 〈i1^*,false〉
237 (* notation < "a \sup ⊛" non associative with precedence 90 for @{'lk $a}.*)
238 interpretation "lk" 'lk a = (lk ? a).
239 notation "a^⊛" non associative with precedence 90 for @{'lk $a}.
242 lemma ostar_true: ∀S.∀i:pitem S.
243 〈i,true〉^⊛ = 〈(\fst (•i))^*, true〉.
246 lemma ostar_false: ∀S.∀i:pitem S.
247 〈i,false〉^⊛ = 〈i^*, false〉.
250 lemma erase_ostar: ∀S.∀e:pre S.
251 |\fst (e^⊛)| = |\fst e|^*.
254 lemma sem_odot_true: ∀S:DeqSet.∀e1:pre S.∀i.
255 \sem{e1 ⊙ 〈i,true〉} =1 \sem{e1 ▹ i} ∪ { [ ] }.
257 cut (e1 ⊙ 〈i,true〉 = 〈\fst (e1 ▹ i), \snd(e1 ▹ i) ∨ true〉) [//]
258 #H >H cases (e1 ▹ i) #i1 #b1 cases b1
259 [>sem_pre_true @eqP_trans [||@eqP_sym @union_assoc]
265 lemma eq_odot_false: ∀S:DeqSet.∀e1:pre S.∀i.
266 e1 ⊙ 〈i,false〉 = e1 ▹ i.
268 cut (e1 ⊙ 〈i,false〉 = 〈\fst (e1 ▹ i), \snd(e1 ▹ i) ∨ false〉) [//]
269 cases (e1 ▹ i) #i1 #b1 cases b1 #H @H
273 ∀S.∀e1,e2: pre S. \sem{e1 ⊙ e2} =1 \sem{e1}· \sem{|\fst e2|} ∪ \sem{e2}.
276 @eqP_trans [|@sem_odot_true]
277 @eqP_trans [||@union_assoc] @eqP_union_r @odot_dot_aux //
278 |>sem_pre_false >eq_odot_false @odot_dot_aux //
283 theorem sem_ostar: ∀S.∀e:pre S.
284 \sem{e^⊛} =1 \sem{e} · \sem{|\fst e|}^*.
286 [>sem_pre_true >sem_pre_true >sem_star >erase_bull
287 @eqP_trans [|@eqP_union_r[|@cat_ext_l [|@minus_eps_pre_aux //]]]
288 @eqP_trans [|@eqP_union_r [|@distr_cat_r]]
289 @eqP_trans [||@eqP_sym @distr_cat_r]
290 @eqP_trans [|@union_assoc] @eqP_union_l
291 @eqP_trans [||@eqP_sym @epsilon_cat_l] @eqP_sym @star_fix_eps
292 |>sem_pre_false >sem_pre_false >sem_star /2/