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 *)
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15 include "ground/xoa/or_3.ma".
16 include "ground/xoa/ex_3_1.ma".
17 include "ground/xoa/ex_4_2.ma".
18 include "ground/notation/relations/runion_3.ma".
19 include "ground/arith/nat_plus.ma".
20 include "ground/arith/nat_le_max.ma".
21 include "ground/relocation/rtmap_isfin.ma".
22 include "ground/relocation/rtmap_sle.ma".
24 coinductive sor: relation3 rtmap rtmap rtmap ≝
25 | sor_pp: ∀f1,f2,f,g1,g2,g. sor f1 f2 f → ⫯f1 = g1 → ⫯f2 = g2 → ⫯f = g → sor g1 g2 g
26 | sor_np: ∀f1,f2,f,g1,g2,g. sor f1 f2 f → ↑f1 = g1 → ⫯f2 = g2 → ↑f = g → sor g1 g2 g
27 | sor_pn: ∀f1,f2,f,g1,g2,g. sor f1 f2 f → ⫯f1 = g1 → ↑f2 = g2 → ↑f = g → sor g1 g2 g
28 | sor_nn: ∀f1,f2,f,g1,g2,g. sor f1 f2 f → ↑f1 = g1 → ↑f2 = g2 → ↑f = g → sor g1 g2 g
31 interpretation "union (rtmap)"
32 'RUnion f1 f2 f = (sor f1 f2 f).
34 (* Basic inversion lemmas ***************************************************)
36 lemma sor_inv_ppx: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f1,f2. ⫯f1 = g1 → ⫯f2 = g2 →
37 ∃∃f. f1 ⋓ f2 ≘ f & ⫯f = g.
38 #g1 #g2 #g * -g1 -g2 -g
39 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #x1 #x2 #Hx1 #Hx2 destruct
40 try (>(injective_push … Hx1) -x1) try (>(injective_next … Hx1) -x1)
41 try elim (discr_push_next … Hx1) try elim (discr_next_push … Hx1)
42 try (>(injective_push … Hx2) -x2) try (>(injective_next … Hx2) -x2)
43 try elim (discr_push_next … Hx2) try elim (discr_next_push … Hx2)
44 /2 width=3 by ex2_intro/
47 lemma sor_inv_npx: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f1,f2. ↑f1 = g1 → ⫯f2 = g2 →
48 ∃∃f. f1 ⋓ f2 ≘ f & ↑f = g.
49 #g1 #g2 #g * -g1 -g2 -g
50 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #x1 #x2 #Hx1 #Hx2 destruct
51 try (>(injective_push … Hx1) -x1) try (>(injective_next … Hx1) -x1)
52 try elim (discr_push_next … Hx1) try elim (discr_next_push … Hx1)
53 try (>(injective_push … Hx2) -x2) try (>(injective_next … Hx2) -x2)
54 try elim (discr_push_next … Hx2) try elim (discr_next_push … Hx2)
55 /2 width=3 by ex2_intro/
58 lemma sor_inv_pnx: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f1,f2. ⫯f1 = g1 → ↑f2 = g2 →
59 ∃∃f. f1 ⋓ f2 ≘ f & ↑f = g.
60 #g1 #g2 #g * -g1 -g2 -g
61 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #x1 #x2 #Hx1 #Hx2 destruct
62 try (>(injective_push … Hx1) -x1) try (>(injective_next … Hx1) -x1)
63 try elim (discr_push_next … Hx1) try elim (discr_next_push … Hx1)
64 try (>(injective_push … Hx2) -x2) try (>(injective_next … Hx2) -x2)
65 try elim (discr_push_next … Hx2) try elim (discr_next_push … Hx2)
66 /2 width=3 by ex2_intro/
69 lemma sor_inv_nnx: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f1,f2. ↑f1 = g1 → ↑f2 = g2 →
70 ∃∃f. f1 ⋓ f2 ≘ f & ↑f = g.
71 #g1 #g2 #g * -g1 -g2 -g
72 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #x1 #x2 #Hx1 #Hx2 destruct
73 try (>(injective_push … Hx1) -x1) try (>(injective_next … Hx1) -x1)
74 try elim (discr_push_next … Hx1) try elim (discr_next_push … Hx1)
75 try (>(injective_push … Hx2) -x2) try (>(injective_next … Hx2) -x2)
76 try elim (discr_push_next … Hx2) try elim (discr_next_push … Hx2)
77 /2 width=3 by ex2_intro/
80 (* Advanced inversion lemmas ************************************************)
82 lemma sor_inv_ppn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
83 ∀f1,f2,f. ⫯f1 = g1 → ⫯f2 = g2 → ↑f = g → ⊥.
84 #g1 #g2 #g #H #f1 #f2 #f #H1 #H2 #H0
85 elim (sor_inv_ppx … H … H1 H2) -g1 -g2 #x #_ #H destruct
86 /2 width=3 by discr_push_next/
89 lemma sor_inv_nxp: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
90 ∀f1,f. ↑f1 = g1 → ⫯f = g → ⊥.
91 #g1 #g2 #g #H #f1 #f #H1 #H0
92 elim (pn_split g2) * #f2 #H2
93 [ elim (sor_inv_npx … H … H1 H2)
94 | elim (sor_inv_nnx … H … H1 H2)
95 ] -g1 -g2 #x #_ #H destruct
96 /2 width=3 by discr_next_push/
99 lemma sor_inv_xnp: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
100 ∀f2,f. ↑f2 = g2 → ⫯f = g → ⊥.
101 #g1 #g2 #g #H #f2 #f #H2 #H0
102 elim (pn_split g1) * #f1 #H1
103 [ elim (sor_inv_pnx … H … H1 H2)
104 | elim (sor_inv_nnx … H … H1 H2)
105 ] -g1 -g2 #x #_ #H destruct
106 /2 width=3 by discr_next_push/
109 lemma sor_inv_ppp: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
110 ∀f1,f2,f. ⫯f1 = g1 → ⫯f2 = g2 → ⫯f = g → f1 ⋓ f2 ≘ f.
111 #g1 #g2 #g #H #f1 #f2 #f #H1 #H2 #H0
112 elim (sor_inv_ppx … H … H1 H2) -g1 -g2 #x #Hx #H destruct
113 <(injective_push … H) -f //
116 lemma sor_inv_npn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
117 ∀f1,f2,f. ↑f1 = g1 → ⫯f2 = g2 → ↑f = g → f1 ⋓ f2 ≘ f.
118 #g1 #g2 #g #H #f1 #f2 #f #H1 #H2 #H0
119 elim (sor_inv_npx … H … H1 H2) -g1 -g2 #x #Hx #H destruct
120 <(injective_next … H) -f //
123 lemma sor_inv_pnn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
124 ∀f1,f2,f. ⫯f1 = g1 → ↑f2 = g2 → ↑f = g → f1 ⋓ f2 ≘ f.
125 #g1 #g2 #g #H #f1 #f2 #f #H1 #H2 #H0
126 elim (sor_inv_pnx … H … H1 H2) -g1 -g2 #x #Hx #H destruct
127 <(injective_next … H) -f //
130 lemma sor_inv_nnn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
131 ∀f1,f2,f. ↑f1 = g1 → ↑f2 = g2 → ↑f = g → f1 ⋓ f2 ≘ f.
132 #g1 #g2 #g #H #f1 #f2 #f #H1 #H2 #H0
133 elim (sor_inv_nnx … H … H1 H2) -g1 -g2 #x #Hx #H destruct
134 <(injective_next … H) -f //
137 lemma sor_inv_pxp: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
138 ∀f1,f. ⫯f1 = g1 → ⫯f = g →
139 ∃∃f2. f1 ⋓ f2 ≘ f & ⫯f2 = g2.
140 #g1 #g2 #g #H #f1 #f #H1 #H0
141 elim (pn_split g2) * #f2 #H2
142 [ /3 width=7 by sor_inv_ppp, ex2_intro/
143 | elim (sor_inv_xnp … H … H2 H0)
147 lemma sor_inv_xpp: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
148 ∀f2,f. ⫯f2 = g2 → ⫯f = g →
149 ∃∃f1. f1 ⋓ f2 ≘ f & ⫯f1 = g1.
150 #g1 #g2 #g #H #f2 #f #H2 #H0
151 elim (pn_split g1) * #f1 #H1
152 [ /3 width=7 by sor_inv_ppp, ex2_intro/
153 | elim (sor_inv_nxp … H … H1 H0)
157 lemma sor_inv_pxn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
158 ∀f1,f. ⫯f1 = g1 → ↑f = g →
159 ∃∃f2. f1 ⋓ f2 ≘ f & ↑f2 = g2.
160 #g1 #g2 #g #H #f1 #f #H1 #H0
161 elim (pn_split g2) * #f2 #H2
162 [ elim (sor_inv_ppn … H … H1 H2 H0)
163 | /3 width=7 by sor_inv_pnn, ex2_intro/
167 lemma sor_inv_xpn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
168 ∀f2,f. ⫯f2 = g2 → ↑f = g →
169 ∃∃f1. f1 ⋓ f2 ≘ f & ↑f1 = g1.
170 #g1 #g2 #g #H #f2 #f #H2 #H0
171 elim (pn_split g1) * #f1 #H1
172 [ elim (sor_inv_ppn … H … H1 H2 H0)
173 | /3 width=7 by sor_inv_npn, ex2_intro/
177 lemma sor_inv_xxp: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f. ⫯f = g →
178 ∃∃f1,f2. f1 ⋓ f2 ≘ f & ⫯f1 = g1 & ⫯f2 = g2.
180 elim (pn_split g1) * #f1 #H1
181 [ elim (sor_inv_pxp … H … H1 H0) -g /2 width=5 by ex3_2_intro/
182 | elim (sor_inv_nxp … H … H1 H0)
186 lemma sor_inv_nxn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
187 ∀f1,f. ↑f1 = g1 → ↑f = g →
188 (∃∃f2. f1 ⋓ f2 ≘ f & ⫯f2 = g2) ∨
189 ∃∃f2. f1 ⋓ f2 ≘ f & ↑f2 = g2.
190 #g1 #g2 elim (pn_split g2) *
191 /4 width=7 by sor_inv_npn, sor_inv_nnn, ex2_intro, or_intror, or_introl/
194 lemma sor_inv_xnn: ∀g1,g2,g. g1 ⋓ g2 ≘ g →
195 ∀f2,f. ↑f2 = g2 → ↑f = g →
196 (∃∃f1. f1 ⋓ f2 ≘ f & ⫯f1 = g1) ∨
197 ∃∃f1. f1 ⋓ f2 ≘ f & ↑f1 = g1.
198 #g1 elim (pn_split g1) *
199 /4 width=7 by sor_inv_pnn, sor_inv_nnn, ex2_intro, or_intror, or_introl/
202 lemma sor_inv_xxn: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f. ↑f = g →
203 ∨∨ ∃∃f1,f2. f1 ⋓ f2 ≘ f & ↑f1 = g1 & ⫯f2 = g2
204 | ∃∃f1,f2. f1 ⋓ f2 ≘ f & ⫯f1 = g1 & ↑f2 = g2
205 | ∃∃f1,f2. f1 ⋓ f2 ≘ f & ↑f1 = g1 & ↑f2 = g2.
207 elim (pn_split g1) * #f1 #H1
208 [ elim (sor_inv_pxn … H … H1 H0) -g
209 /3 width=5 by or3_intro1, ex3_2_intro/
210 | elim (sor_inv_nxn … H … H1 H0) -g *
211 /3 width=5 by or3_intro0, or3_intro2, ex3_2_intro/
215 (* Main inversion lemmas ****************************************************)
217 corec theorem sor_mono: ∀f1,f2,x,y. f1 ⋓ f2 ≘ x → f1 ⋓ f2 ≘ y → x ≡ y.
218 #f1 #f2 #x #y * -f1 -f2 -x
219 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #H
220 [ cases (sor_inv_ppx … H … H1 H2)
221 | cases (sor_inv_npx … H … H1 H2)
222 | cases (sor_inv_pnx … H … H1 H2)
223 | cases (sor_inv_nnx … H … H1 H2)
225 /3 width=5 by eq_push, eq_next/
228 (* Basic properties *********************************************************)
230 corec lemma sor_eq_repl_back1: ∀f2,f. eq_repl_back … (λf1. f1 ⋓ f2 ≘ f).
231 #f2 #f #f1 * -f1 -f2 -f
232 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0 #x #Hx
233 try cases (eq_inv_px … Hx … H1) try cases (eq_inv_nx … Hx … H1) -g1
234 /3 width=7 by sor_pp, sor_np, sor_pn, sor_nn/
237 lemma sor_eq_repl_fwd1: ∀f2,f. eq_repl_fwd … (λf1. f1 ⋓ f2 ≘ f).
238 #f2 #f @eq_repl_sym /2 width=3 by sor_eq_repl_back1/
241 corec lemma sor_eq_repl_back2: ∀f1,f. eq_repl_back … (λf2. f1 ⋓ f2 ≘ f).
242 #f1 #f #f2 * -f1 -f2 -f
243 #f1 #f2 #f #g1 #g2 #g #Hf #H #H2 #H0 #x #Hx
244 try cases (eq_inv_px … Hx … H2) try cases (eq_inv_nx … Hx … H2) -g2
245 /3 width=7 by sor_pp, sor_np, sor_pn, sor_nn/
248 lemma sor_eq_repl_fwd2: ∀f1,f. eq_repl_fwd … (λf2. f1 ⋓ f2 ≘ f).
249 #f1 #f @eq_repl_sym /2 width=3 by sor_eq_repl_back2/
252 corec lemma sor_eq_repl_back3: ∀f1,f2. eq_repl_back … (λf. f1 ⋓ f2 ≘ f).
253 #f1 #f2 #f * -f1 -f2 -f
254 #f1 #f2 #f #g1 #g2 #g #Hf #H #H2 #H0 #x #Hx
255 try cases (eq_inv_px … Hx … H0) try cases (eq_inv_nx … Hx … H0) -g
256 /3 width=7 by sor_pp, sor_np, sor_pn, sor_nn/
259 lemma sor_eq_repl_fwd3: ∀f1,f2. eq_repl_fwd … (λf. f1 ⋓ f2 ≘ f).
260 #f1 #f2 @eq_repl_sym /2 width=3 by sor_eq_repl_back3/
263 corec lemma sor_idem: ∀f. f ⋓ f ≘ f.
264 #f cases (pn_split f) * #g #H
265 [ @(sor_pp … H H H) | @(sor_nn … H H H) ] -H //
268 corec lemma sor_comm: ∀f1,f2,f. f1 ⋓ f2 ≘ f → f2 ⋓ f1 ≘ f.
269 #f1 #f2 #f * -f1 -f2 -f
270 #f1 #f2 #f #g1 #g2 #g #Hf * * * -g1 -g2 -g
271 [ @sor_pp | @sor_pn | @sor_np | @sor_nn ] /2 width=7 by/
274 (* Properties with tail *****************************************************)
276 lemma sor_tl: ∀f1,f2,f. f1 ⋓ f2 ≘ f → ⫱f1 ⋓ ⫱f2 ≘ ⫱f.
277 #f1 cases (pn_split f1) * #g1 #H1
278 #f2 cases (pn_split f2) * #g2 #H2
280 [ cases (sor_inv_ppx … Hf … H1 H2)
281 | cases (sor_inv_pnx … Hf … H1 H2)
282 | cases (sor_inv_npx … Hf … H1 H2)
283 | cases (sor_inv_nnx … Hf … H1 H2)
284 ] -Hf #g #Hg #H destruct //
287 lemma sor_xxn_tl: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f. ↑f = g →
288 (∃∃f1,f2. f1 ⋓ f2 ≘ f & ↑f1 = g1 & ⫱g2 = f2) ∨
289 (∃∃f1,f2. f1 ⋓ f2 ≘ f & ⫱g1 = f1 & ↑f2 = g2).
290 #g1 #g2 #g #H #f #H0 elim (sor_inv_xxn … H … H0) -H -H0 *
291 /3 width=5 by ex3_2_intro, or_introl, or_intror/
294 lemma sor_xnx_tl: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f2. ↑f2 = g2 →
295 ∃∃f1,f. f1 ⋓ f2 ≘ f & ⫱g1 = f1 & ↑f = g.
296 #g1 elim (pn_split g1) * #f1 #H1 #g2 #g #H #f2 #H2
297 [ elim (sor_inv_pnx … H … H1 H2) | elim (sor_inv_nnx … H … H1 H2) ] -g2
298 /3 width=5 by ex3_2_intro/
301 lemma sor_nxx_tl: ∀g1,g2,g. g1 ⋓ g2 ≘ g → ∀f1. ↑f1 = g1 →
302 ∃∃f2,f. f1 ⋓ f2 ≘ f & ⫱g2 = f2 & ↑f = g.
303 #g1 #g2 elim (pn_split g2) * #f2 #H2 #g #H #f1 #H1
304 [ elim (sor_inv_npx … H … H1 H2) | elim (sor_inv_nnx … H … H1 H2) ] -g1
305 /3 width=5 by ex3_2_intro/
308 (* Properties with iterated tail ********************************************)
310 lemma sor_tls: ∀f1,f2,f. f1 ⋓ f2 ≘ f →
311 ∀n. ⫱*[n]f1 ⋓ ⫱*[n]f2 ≘ ⫱*[n]f.
312 #f1 #f2 #f #Hf #n @(nat_ind_succ … n) -n
313 /2 width=1 by sor_tl/
316 (* Properies with test for identity *****************************************)
318 corec lemma sor_isid_sn: ∀f1. 𝐈❪f1❫ → ∀f2. f1 ⋓ f2 ≘ f2.
320 #f1 #g1 #Hf1 #H1 #f2 cases (pn_split f2) *
321 /3 width=7 by sor_pp, sor_pn/
324 corec lemma sor_isid_dx: ∀f2. 𝐈❪f2❫ → ∀f1. f1 ⋓ f2 ≘ f1.
326 #f2 #g2 #Hf2 #H2 #f1 cases (pn_split f1) *
327 /3 width=7 by sor_pp, sor_np/
330 lemma sor_isid: ∀f1,f2,f. 𝐈❪f1❫ → 𝐈❪f2❫ → 𝐈❪f❫ → f1 ⋓ f2 ≘ f.
331 /4 width=3 by sor_eq_repl_back2, sor_eq_repl_back1, isid_inv_eq_repl/ qed.
333 (* Inversion lemmas with tail ***********************************************)
335 lemma sor_inv_tl_sn: ∀f1,f2,f. ⫱f1 ⋓ f2 ≘ f → f1 ⋓ ↑f2 ≘ ↑f.
336 #f1 #f2 #f elim (pn_split f1) *
337 #g1 #H destruct /2 width=7 by sor_pn, sor_nn/
340 lemma sor_inv_tl_dx: ∀f1,f2,f. f1 ⋓ ⫱f2 ≘ f → ↑f1 ⋓ f2 ≘ ↑f.
341 #f1 #f2 #f elim (pn_split f2) *
342 #g2 #H destruct /2 width=7 by sor_np, sor_nn/
345 (* Inversion lemmas with test for identity **********************************)
347 lemma sor_isid_inv_sn: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐈❪f1❫ → f2 ≡ f.
348 /3 width=4 by sor_isid_sn, sor_mono/
351 lemma sor_isid_inv_dx: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐈❪f2❫ → f1 ≡ f.
352 /3 width=4 by sor_isid_dx, sor_mono/
355 corec lemma sor_fwd_isid1: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f1❫.
356 #f1 #f2 #f * -f1 -f2 -f
357 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H #Hg
358 [ /4 width=6 by isid_inv_push, isid_push/ ]
359 cases (isid_inv_next … Hg … H)
362 corec lemma sor_fwd_isid2: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f2❫.
363 #f1 #f2 #f * -f1 -f2 -f
364 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H #Hg
365 [ /4 width=6 by isid_inv_push, isid_push/ ]
366 cases (isid_inv_next … Hg … H)
369 lemma sor_inv_isid3: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐈❪f❫ → 𝐈❪f1❫ ∧ 𝐈❪f2❫.
370 /3 width=4 by sor_fwd_isid2, sor_fwd_isid1, conj/ qed-.
372 (* Properties with finite colength assignment *******************************)
374 lemma sor_fcla_ex: ∀f1,n1. 𝐂❪f1❫ ≘ n1 → ∀f2,n2. 𝐂❪f2❫ ≘ n2 →
375 ∃∃f,n. f1 ⋓ f2 ≘ f & 𝐂❪f❫ ≘ n & (n1 ∨ n2) ≤ n & n ≤ n1 + n2.
376 #f1 #n1 #Hf1 elim Hf1 -f1 -n1 /3 width=6 by sor_isid_sn, ex4_2_intro/
377 #f1 #n1 #Hf1 #IH #f2 #n2 * -f2 -n2 /3 width=6 by fcla_push, fcla_next, ex4_2_intro, sor_isid_dx/
378 #f2 #n2 #Hf2 elim (IH … Hf2) -IH -Hf2 -Hf1 [2,4: #f #n <nplus_succ_dx ] (**) (* full auto fails *)
379 [ /3 width=7 by fcla_next, sor_pn, nle_max_sn_succ_dx, nle_succ_bi, ex4_2_intro/
380 | /4 width=7 by fcla_next, sor_nn, nle_succ_dx, nle_succ_bi, ex4_2_intro/
381 | /3 width=7 by fcla_push, sor_pp, ex4_2_intro/
382 | /3 width=7 by fcla_next, sor_np, nle_max_sn_succ_sn, nle_succ_bi, ex4_2_intro/
386 lemma sor_fcla: ∀f1,n1. 𝐂❪f1❫ ≘ n1 → ∀f2,n2. 𝐂❪f2❫ ≘ n2 → ∀f. f1 ⋓ f2 ≘ f →
387 ∃∃n. 𝐂❪f❫ ≘ n & (n1 ∨ n2) ≤ n & n ≤ n1 + n2.
388 #f1 #n1 #Hf1 #f2 #n2 #Hf2 #f #Hf elim (sor_fcla_ex … Hf1 … Hf2) -Hf1 -Hf2
389 /4 width=6 by sor_mono, fcla_eq_repl_back, ex3_intro/
392 (* Forward lemmas with finite colength **************************************)
394 lemma sor_fwd_fcla_sn_ex: ∀f,n. 𝐂❪f❫ ≘ n → ∀f1,f2. f1 ⋓ f2 ≘ f →
395 ∃∃n1. 𝐂❪f1❫ ≘ n1 & n1 ≤ n.
396 #f #n #H elim H -f -n
397 [ /4 width=4 by sor_fwd_isid1, fcla_isid, ex2_intro/
398 | #f #n #_ #IH #f1 #f2 #H
399 elim (sor_inv_xxp … H) -H [ |*: // ] #g1 #g2 #Hf #H1 #H2 destruct
400 elim (IH … Hf) -f /3 width=3 by fcla_push, ex2_intro/
401 | #f #n #_ #IH #f1 #f2 #H
402 elim (sor_inv_xxn … H) -H [1,3,4: * |*: // ] #g1 #g2 #Hf #H1 #H2 destruct
403 elim (IH … Hf) -f /3 width=3 by fcla_push, fcla_next, nle_succ_bi, nle_succ_dx, ex2_intro/
407 lemma sor_fwd_fcla_dx_ex: ∀f,n. 𝐂❪f❫ ≘ n → ∀f1,f2. f1 ⋓ f2 ≘ f →
408 ∃∃n2. 𝐂❪f2❫ ≘ n2 & n2 ≤ n.
409 /3 width=4 by sor_fwd_fcla_sn_ex, sor_comm/ qed-.
411 (* Properties with test for finite colength *********************************)
413 lemma sor_isfin_ex: ∀f1,f2. 𝐅❪f1❫ → 𝐅❪f2❫ → ∃∃f. f1 ⋓ f2 ≘ f & 𝐅❪f❫.
414 #f1 #f2 * #n1 #H1 * #n2 #H2 elim (sor_fcla_ex … H1 … H2) -H1 -H2
415 /3 width=4 by ex2_intro, ex_intro/
418 lemma sor_isfin: ∀f1,f2. 𝐅❪f1❫ → 𝐅❪f2❫ → ∀f. f1 ⋓ f2 ≘ f → 𝐅❪f❫.
419 #f1 #f2 #Hf1 #Hf2 #f #Hf elim (sor_isfin_ex … Hf1 … Hf2) -Hf1 -Hf2
420 /3 width=6 by sor_mono, isfin_eq_repl_back/
423 (* Forward lemmas with test for finite colength *****************************)
425 lemma sor_fwd_isfin_sn: ∀f. 𝐅❪f❫ → ∀f1,f2. f1 ⋓ f2 ≘ f → 𝐅❪f1❫.
426 #f * #n #Hf #f1 #f2 #H
427 elim (sor_fwd_fcla_sn_ex … Hf … H) -f -f2 /2 width=2 by ex_intro/
430 lemma sor_fwd_isfin_dx: ∀f. 𝐅❪f❫ → ∀f1,f2. f1 ⋓ f2 ≘ f → 𝐅❪f2❫.
431 #f * #n #Hf #f1 #f2 #H
432 elim (sor_fwd_fcla_dx_ex … Hf … H) -f -f1 /2 width=2 by ex_intro/
435 (* Inversion lemmas with test for finite colength ***************************)
437 lemma sor_inv_isfin3: ∀f1,f2,f. f1 ⋓ f2 ≘ f → 𝐅❪f❫ → 𝐅❪f1❫ ∧ 𝐅❪f2❫.
438 /3 width=4 by sor_fwd_isfin_dx, sor_fwd_isfin_sn, conj/ qed-.
440 (* Inversion lemmas with inclusion ******************************************)
442 corec lemma sor_inv_sle_sn: ∀f1,f2,f. f1 ⋓ f2 ≘ f → f1 ⊆ f.
443 #f1 #f2 #f * -f1 -f2 -f
444 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0
445 /3 width=5 by sle_push, sle_next, sle_weak/
448 corec lemma sor_inv_sle_dx: ∀f1,f2,f. f1 ⋓ f2 ≘ f → f2 ⊆ f.
449 #f1 #f2 #f * -f1 -f2 -f
450 #f1 #f2 #f #g1 #g2 #g #Hf #H1 #H2 #H0
451 /3 width=5 by sle_push, sle_next, sle_weak/
454 lemma sor_inv_sle_sn_trans: ∀f1,f2,f. f1 ⋓ f2 ≘ f → ∀g. g ⊆ f1 → g ⊆ f.
455 /3 width=4 by sor_inv_sle_sn, sle_trans/ qed-.
457 lemma sor_inv_sle_dx_trans: ∀f1,f2,f. f1 ⋓ f2 ≘ f → ∀g. g ⊆ f2 → g ⊆ f.
458 /3 width=4 by sor_inv_sle_dx, sle_trans/ qed-.
460 axiom sor_inv_sle: ∀f1,f2,f. f1 ⋓ f2 ≘ f → ∀g. f1 ⊆ g → f2 ⊆ g → f ⊆ g.
462 (* Properties with inclusion ************************************************)
464 corec lemma sor_sle_dx: ∀f1,f2. f1 ⊆ f2 → f1 ⋓ f2 ≘ f2.
465 #f1 #f2 * -f1 -f2 /3 width=7 by sor_pp, sor_nn, sor_pn/
468 corec lemma sor_sle_sn: ∀f1,f2. f1 ⊆ f2 → f2 ⋓ f1 ≘ f2.
469 #f1 #f2 * -f1 -f2 /3 width=7 by sor_pp, sor_nn, sor_np/
472 (* Main properties **********************************************************)
474 axiom monotonic_sle_sor: ∀f1,g1. f1 ⊆ g1 → ∀f2,g2. f2 ⊆ g2 →
475 ∀f. f1 ⋓ f2 ≘ f → ∀g. g1 ⋓ g2 ≘ g → f ⊆ g.
477 axiom sor_assoc_dx: ∀f0,f3,f4. f0 ⋓ f3 ≘ f4 →
478 ∀f1,f2. f1 ⋓ f2 ≘ f0 →
479 ∀f. f2 ⋓ f3 ≘ f → f1 ⋓ f ≘ f4.
481 axiom sor_assoc_sn: ∀f1,f0,f4. f1 ⋓ f0 ≘ f4 →
482 ∀f2, f3. f2 ⋓ f3 ≘ f0 →
483 ∀f. f1 ⋓ f2 ≘ f → f ⋓ f3 ≘ f4.
485 lemma sor_comm_23: ∀f0,f1,f2,f3,f4,f.
486 f0⋓f4 ≘ f1 → f1⋓f2 ≘ f → f0⋓f2 ≘ f3 → f3⋓f4 ≘ f.
487 /4 width=6 by sor_comm, sor_assoc_dx/ qed-.
489 corec theorem sor_comm_23_idem: ∀f0,f1,f2. f0 ⋓ f1 ≘ f2 →
490 ∀f. f1 ⋓ f2 ≘ f → f1 ⋓ f0 ≘ f.
491 #f0 #f1 #f2 * -f0 -f1 -f2
492 #f0 #f1 #f2 #g0 #g1 #g2 #Hf2 #H0 #H1 #H2 #g #Hg
493 [ cases (sor_inv_ppx … Hg … H1 H2)
494 | cases (sor_inv_pnx … Hg … H1 H2)
495 | cases (sor_inv_nnx … Hg … H1 H2)
496 | cases (sor_inv_nnx … Hg … H1 H2)
498 /3 width=7 by sor_nn, sor_np, sor_pn, sor_pp/
501 corec theorem sor_coll_dx: ∀f1,f2,f. f1 ⋓ f2 ≘ f → ∀g1,g2,g. g1 ⋓ g2 ≘ g →
502 ∀g0. g1 ⋓ g0 ≘ f1 → g2 ⋓ g0 ≘ f2 → g ⋓ g0 ≘ f.
503 #f1 #f2 #f cases (pn_split f) * #x #Hx #Hf #g1 #g2 #g #Hg #g0 #Hf1 #Hf2
504 [ cases (sor_inv_xxp … Hf … Hx) -Hf #x1 #x2 #Hf #Hx1 #Hx2
505 cases (sor_inv_xxp … Hf1 … Hx1) -f1 #y1 #y0 #Hf1 #Hy1 #Hy0
506 cases (sor_inv_xpp … Hf2 … Hy0 … Hx2) -f2 #y2 #Hf2 #Hy2
507 cases (sor_inv_ppx … Hg … Hy1 Hy2) -g1 -g2 #y #Hg #Hy
508 @(sor_pp … Hy Hy0 Hx) -g -g0 -f /2 width=8 by/
509 | cases (pn_split g) * #y #Hy
510 [ cases (sor_inv_xxp … Hg … Hy) -Hg #y1 #y2 #Hg #Hy1 #Hy2
511 cases (sor_xxn_tl … Hf … Hx) * #x1 #x2 #_ #Hx1 #Hx2
512 [ cases (sor_inv_pxn … Hf1 … Hy1 Hx1) -g1 #y0 #Hf1 #Hy0
513 cases (sor_inv_pnx … Hf2 … Hy2 Hy0) -g2 -x2 #x2 #Hf2 #Hx2
514 | cases (sor_inv_pxn … Hf2 … Hy2 Hx2) -g2 #y0 #Hf2 #Hy0
515 cases (sor_inv_pnx … Hf1 … Hy1 Hy0) -g1 -x1 #x1 #Hf1 #Hx1
517 lapply (sor_inv_nnn … Hf … Hx1 Hx2 Hx) -f1 -f2 #Hf
518 @(sor_pn … Hy Hy0 Hx) -g -g0 -f /2 width=8 by/
519 | lapply (sor_tl … Hf) -Hf #Hf
520 lapply (sor_tl … Hg) -Hg #Hg
521 lapply (sor_tl … Hf1) -Hf1 #Hf1
522 lapply (sor_tl … Hf2) -Hf2 #Hf2
523 cases (pn_split g0) * #y0 #Hy0
524 [ @(sor_np … Hy Hy0 Hx) /2 width=8 by/
525 | @(sor_nn … Hy Hy0 Hx) /2 width=8 by/
531 corec theorem sor_distr_dx: ∀g0,g1,g2,g. g1 ⋓ g2 ≘ g →
532 ∀f1,f2,f. g1 ⋓ g0 ≘ f1 → g2 ⋓ g0 ≘ f2 → g ⋓ g0 ≘ f →
534 #g0 cases (pn_split g0) * #y0 #H0 #g1 #g2 #g
535 [ * -g1 -g2 -g #y1 #y2 #y #g1 #g2 #g #Hy #Hy1 #Hy2 #Hy #f1 #f2 #f #Hf1 #Hf2 #Hf
536 [ cases (sor_inv_ppx … Hf1 … Hy1 H0) -g1
537 cases (sor_inv_ppx … Hf2 … Hy2 H0) -g2
538 cases (sor_inv_ppx … Hf … Hy H0) -g
539 | cases (sor_inv_npx … Hf1 … Hy1 H0) -g1
540 cases (sor_inv_ppx … Hf2 … Hy2 H0) -g2
541 cases (sor_inv_npx … Hf … Hy H0) -g
542 | cases (sor_inv_ppx … Hf1 … Hy1 H0) -g1
543 cases (sor_inv_npx … Hf2 … Hy2 H0) -g2
544 cases (sor_inv_npx … Hf … Hy H0) -g
545 | cases (sor_inv_npx … Hf1 … Hy1 H0) -g1
546 cases (sor_inv_npx … Hf2 … Hy2 H0) -g2
547 cases (sor_inv_npx … Hf … Hy H0) -g
548 ] -g0 #y #Hy #H #y2 #Hy2 #H2 #y1 #Hy1 #H1
549 /3 width=8 by sor_nn, sor_np, sor_pn, sor_pp/
550 | #H #f1 #f2 #f #Hf1 #Hf2 #Hf
551 cases (sor_xnx_tl … Hf1 … H0) -Hf1
552 cases (sor_xnx_tl … Hf2 … H0) -Hf2
553 cases (sor_xnx_tl … Hf … H0) -Hf
554 -g0 #y #x #Hx #Hy #H #y2 #x2 #Hx2 #Hy2 #H2 #y1 #x1 #Hx1 #Hy1 #H1
555 /4 width=8 by sor_tl, sor_nn/