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 "models/q_bars.ma".
17 lemma initial_shift_same_values:
18 ∀l1:q_f.∀init.init < start l1 →
20 (mk_q_f init (〈\fst (unpos (start l1 - init) ?),OQ〉:: bars l1)).
21 [apply hide; apply q_lt_minus; rewrite > q_plus_sym; rewrite > q_plus_OQ; assumption]
22 intros; generalize in ⊢ (? ? (? ? (? ? (? ? ? (? ? ? (? ? %)) ?) ?))); intro;
23 cases (unpos (start l1-init) H1); intro input;
24 simplify in ⊢ (? ? ? (? ? ? (? ? ? (? (? ? (? ? (? ? ? % ?) ?)) ?))));
25 cases (value (mk_q_f init (〈w,OQ〉::bars l1)) input);
26 simplify in ⊢ (? ? ? (? ? ? %));
27 cases (q_cmp input (start (mk_q_f init (〈w,OQ〉::bars l1)))) in H3;
28 whd in ⊢ (% → ?); simplify in H3;
29 [1: intro; cases H4; clear H4; rewrite > H3;
30 cases (value l1 init); simplify; cases (q_cmp init (start l1)) in H4;
31 [1: cases (?:False); apply (q_lt_corefl init); rewrite > H4 in ⊢ (?? %); apply H;
32 |3: cases (?:False); apply (q_lt_antisym init (start l1)); assumption;
33 |2: whd in ⊢ (% → ?); intro; rewrite > H8; clear H8 H4;
34 rewrite > H7; clear H7; rewrite > (?:\fst w1 = O); [reflexivity]
35 symmetry; apply le_n_O_to_eq;
36 rewrite > (sum_bases_O (mk_q_f init (〈w,OQ〉::bars l1)) (\fst w1)); [apply le_n]
37 clear H6 w2; simplify in H5:(? ? (? ? %));
38 destruct H3; rewrite > q_d_x_x in H5; assumption;]
39 |2: intros; cases (value l1 input); simplify in ⊢ (? ? (? ? ? %) ?);
40 cases (q_cmp input (start l1)) in H5; whd in ⊢ (% → ?);
41 [1: cases (?:False); clear w2 H4 w1 H2 w H1;
42 apply (q_lt_antisym init (start l1)); [assumption] rewrite < H5; assumption
43 |2: intros; rewrite > H6; clear H6; rewrite > H4; reflexivity;
44 |3: cases (?:False); apply (q_lt_antisym input (start l1)); [2: assumption]
45 apply (q_lt_trans ??? H3 H);]
46 |3: intro; cases H4; clear H4;
47 cases (value l1 input); simplify; cases (q_cmp input (start l1)) in H4; whd in ⊢ (% → ?);
48 [1: intro; cases H8; clear H8; rewrite > H11; rewrite > H7; clear H11 H7;
49 simplify in ⊢ (? ? ? (? ? ? (? ? % ? ?)));
50 cut (\fst w1 = S (\fst w2)) as Key; [rewrite > Key; reflexivity;]
51 cut (\fst w2 = O); [2: clear H10;
52 symmetry; apply le_n_O_to_eq; rewrite > (sum_bases_O l1 (\fst w2)); [apply le_n]
53 apply (q_le_trans ??? H9); rewrite < H4; rewrite > q_d_x_x;
54 apply q_eq_to_le; reflexivity;]
55 rewrite > Hcut; clear Hcut H10 H9; simplify in H5 H6;
56 cut (ⅆ[input,init] = Qpos w) as E; [2:
57 rewrite > H2; rewrite < H4; rewrite > q_d_sym;
58 rewrite > q_d_noabs; [reflexivity] apply q_lt_to_le; assumption;]
59 cases (\fst w1) in H5 H6; intros;
60 [1: cases (?:False); clear H5; simplify in H6;
61 apply (q_lt_corefl ⅆ[input,init]);
62 rewrite > E in ⊢ (??%); rewrite < q_plus_OQ in ⊢ (??%);
63 rewrite > q_plus_sym; assumption;
64 |2: cases n in H5 H6; [intros; reflexivity] intros;
65 cases (?:False); clear H6; cases (bars l1) in H5; simplify; intros;
66 [apply (q_pos_OQ one);|apply (q_pos_OQ (\fst b));]
67 apply (q_le_S ??? (sum_bases_ge_OQ ? n1));[apply []|3:apply l]
68 simplify in ⊢ (? (? (? % ?) ?) ?); rewrite < (q_plus_minus (Qpos w));
69 rewrite > q_elim_minus; apply q_le_minus_r;
70 rewrite > q_elim_opp; rewrite < E in ⊢ (??%); assumption;]
71 |2: intros; rewrite > H8; rewrite > H7; clear H8 H7;
72 simplify in H5 H6 ⊢ %;
73 cases (\fst w1) in H5 H6; [intros; reflexivity]
75 [1: intros; simplify; elim n [reflexivity] simplify; assumption;
76 |2: simplify; intros; cases (?:False); clear H6;
77 apply (q_lt_le_incompat (input - init) (Qpos w) );
78 [1: rewrite > H2; do 2 rewrite > q_elim_minus;
79 apply q_lt_plus; rewrite > q_elim_minus;
80 rewrite < q_plus_assoc; rewrite < q_elim_minus;
81 rewrite > q_plus_minus;
82 rewrite > q_plus_OQ; assumption;
83 |2: rewrite < q_d_noabs; [2: apply q_lt_to_le; assumption]
84 rewrite > q_d_sym; apply (q_le_S ???? H5);
85 apply sum_bases_ge_OQ;]]
91 alias symbol "pi2" = "pair pi2".
92 alias symbol "pi1" = "pair pi1".
93 definition rebase_spec ≝
94 ∀l1,l2:q_f.∃p:q_f × q_f.
96 (*len (bars (\fst p)) = len (bars (\snd p))*)
97 (start (\fst p) = start (\snd p))
98 (same_bases (\fst p) (\snd p))
99 (same_values l1 (\fst p))
100 (same_values l2 (\snd p)).
102 definition rebase_spec_simpl ≝
103 λstart.λl1,l2:list bar.λp:(list bar) × (list bar).
105 (same_bases (mk_q_f start (\fst p)) (mk_q_f start (\snd p)))
106 (same_values (mk_q_f start l1) (mk_q_f start (\fst p)))
107 (same_values (mk_q_f start l2) (mk_q_f start (\snd p))).
109 (* a local letin makes russell fail *)
110 definition cb0h : list bar → list bar ≝
111 λl.mk_list (λi.〈\fst (nth l ▭ i),OQ〉) (len l).
114 λP.λp:∃x:(list bar) × (list bar).P x.match p with [ex_introT p _ ⇒ p].
116 definition inject ≝ λP.λp:(list bar) × (list bar).λh:P p. ex_introT ? P p h.
117 coercion inject with 0 1 nocomposites.
119 definition rebase: rebase_spec.
120 intros 2 (f1 f2); cases f1 (s1 l1); cases f2 (s2 l2); clear f1 f2;
122 λs.λl1,l2.λm.λz.len l1 + len l2 < m → rebase_spec_simpl s l1 l2 z);
123 alias symbol "pi1" (instance 34) = "exT \fst".
124 alias symbol "pi1" (instance 21) = "exT \fst".
126 let rec aux (l1,l2:list bar) (n:nat) on n : (list bar) × (list bar) ≝
128 [ O ⇒ 〈 nil ? , nil ? 〉
131 [ nil ⇒ 〈cb0h l2, l2〉
134 [ nil ⇒ 〈l1, cb0h l1〉
136 let base1 ≝ Qpos (\fst he1) in
137 let base2 ≝ Qpos (\fst he2) in
138 let height1 ≝ (\snd he1) in
139 let height2 ≝ (\snd he2) in
140 match q_cmp base1 base2 with
142 let rc ≝ aux tl1 tl2 m in
143 〈he1 :: \fst rc,he2 :: \snd rc〉
145 let rest ≝ base2 - base1 in
146 let rc ≝ aux tl1 (〈\fst (unpos rest ?),height2〉 :: tl2) m in
147 〈〈\fst he1,height1〉 :: \fst rc,〈\fst he1,height2〉 :: \snd rc〉
149 let rest ≝ base1 - base2 in
150 let rc ≝ aux (〈\fst (unpos rest ?),height1〉 :: tl1) tl2 m in
151 〈〈\fst he2,height1〉 :: \fst rc,〈\fst he2,height2〉 :: \snd rc〉
153 in aux : ∀l1,l2,m.∃z.∀s.spec s l1 l2 m z); unfold spec;
154 [9: clearbody aux; unfold spec in aux; clear spec;
156 [1: cases (aux l1 l2 (S (len l1 + len l2)));
157 cases (H1 s1 (le_n ?)); clear H1;
158 exists [apply 〈mk_q_f s1 (\fst w), mk_q_f s2 (\snd w)〉] split;
160 |3: intro; apply (H3 input);
161 |4: intro; rewrite > H in H4;
162 rewrite > (H4 input); reflexivity;]
163 |2: letin l2' ≝ (〈\fst (unpos (s2-s1) ?),OQ〉::l2);[
164 apply q_lt_minus; rewrite > q_plus_sym; rewrite > q_plus_OQ;
166 cases (aux l1 l2' (S (len l1 + len l2')));
167 cases (H1 s1 (le_n ?)); clear H1 aux;
168 exists [apply 〈mk_q_f s1 (\fst w), mk_q_f s1 (\snd w)〉] split;
172 |4: intro; rewrite < (H4 input); clear H3 H4 H2 w;
173 cases (value (mk_q_f s1 l2') input);
174 cases (q_cmp input (start (mk_q_f s1 l2'))) in H1;
176 [1: intros; cases H2; clear H2; whd in ⊢ (??? %);
177 cases (value (mk_q_f s2 l2) input);
178 cases (q_cmp input (start (mk_q_f s2 l2))) in H2;
180 [1: intros; cases H6; clear H6; change with (w1 = w);
183 |1,2: unfold rest; apply q_lt_minus; rewrite > q_plus_sym; rewrite > q_plus_OQ;
190 |8: intros; cases (?:False); apply (not_le_Sn_O ? H1);]