Metamath Proof Explorer


Theorem dya2iocuni

Description: Every open set of ( RR X. RR ) is a union of closed-below open-above dyadic rational rectangular subsets of ( RR X. RR ) . This union must be a countable union by dya2iocct . (Contributed by Thierry Arnoux, 18-Sep-2017)

Ref Expression
Hypotheses sxbrsiga.0 J = topGen ran .
dya2ioc.1 I = x , n x 2 n x + 1 2 n
dya2ioc.2 R = u ran I , v ran I u × v
Assertion dya2iocuni A J × t J c 𝒫 ran R c = A

Proof

Step Hyp Ref Expression
1 sxbrsiga.0 J = topGen ran .
2 dya2ioc.1 I = x , n x 2 n x + 1 2 n
3 dya2ioc.2 R = u ran I , v ran I u × v
4 ssrab2 b ran R | z A z b b A ran R
5 1 2 3 dya2iocrfn R Fn ran I × ran I
6 zex V
7 6 6 mpoex x , n x 2 n x + 1 2 n V
8 2 7 eqeltri I V
9 8 rnex ran I V
10 9 9 xpex ran I × ran I V
11 fnex R Fn ran I × ran I ran I × ran I V R V
12 5 10 11 mp2an R V
13 12 rnex ran R V
14 13 elpw2 b ran R | z A z b b A 𝒫 ran R b ran R | z A z b b A ran R
15 4 14 mpbir b ran R | z A z b b A 𝒫 ran R
16 15 a1i A J × t J b ran R | z A z b b A 𝒫 ran R
17 rex0 ¬ z z b b A
18 rexeq A = z A z b b A z z b b A
19 17 18 mtbiri A = ¬ z A z b b A
20 19 ralrimivw A = b ran R ¬ z A z b b A
21 rabeq0 b ran R | z A z b b A = b ran R ¬ z A z b b A
22 20 21 sylibr A = b ran R | z A z b b A =
23 22 unieqd A = b ran R | z A z b b A =
24 uni0 =
25 23 24 eqtrdi A = b ran R | z A z b b A =
26 0ss A
27 25 26 eqsstrdi A = b ran R | z A z b b A A
28 elequ2 b = p z b z p
29 sseq1 b = p b A p A
30 28 29 anbi12d b = p z b b A z p p A
31 30 rexbidv b = p z A z b b A z A z p p A
32 31 elrab p b ran R | z A z b b A p ran R z A z p p A
33 simpr z p p A p A
34 33 reximi z A z p p A z A p A
35 r19.9rzv A p A z A p A
36 34 35 syl5ibr A z A z p p A p A
37 36 adantld A p ran R z A z p p A p A
38 32 37 syl5bi A p b ran R | z A z b b A p A
39 38 ralrimiv A p b ran R | z A z b b A p A
40 unissb b ran R | z A z b b A A p b ran R | z A z b b A p A
41 39 40 sylibr A b ran R | z A z b b A A
42 27 41 pm2.61ine b ran R | z A z b b A A
43 42 a1i A J × t J b ran R | z A z b b A A
44 1 2 3 dya2iocnei A J × t J m A p ran R m p p A
45 simpl p ran R m p p A p ran R
46 ssel2 p A m p m A
47 46 ancoms m p p A m A
48 47 adantl p ran R m p p A m A
49 simpr p ran R m p p A m p p A
50 elequ1 z = m z p m p
51 50 anbi1d z = m z p p A m p p A
52 51 rspcev m A m p p A z A z p p A
53 48 49 52 syl2anc p ran R m p p A z A z p p A
54 45 53 jca p ran R m p p A p ran R z A z p p A
55 54 32 sylibr p ran R m p p A p b ran R | z A z b b A
56 simprl p ran R m p p A m p
57 55 56 jca p ran R m p p A p b ran R | z A z b b A m p
58 57 reximi2 p ran R m p p A p b ran R | z A z b b A m p
59 44 58 syl A J × t J m A p b ran R | z A z b b A m p
60 eluni2 m b ran R | z A z b b A p b ran R | z A z b b A m p
61 59 60 sylibr A J × t J m A m b ran R | z A z b b A
62 43 61 eqelssd A J × t J b ran R | z A z b b A = A
63 unieq c = b ran R | z A z b b A c = b ran R | z A z b b A
64 63 eqeq1d c = b ran R | z A z b b A c = A b ran R | z A z b b A = A
65 64 rspcev b ran R | z A z b b A 𝒫 ran R b ran R | z A z b b A = A c 𝒫 ran R c = A
66 16 62 65 syl2anc A J × t J c 𝒫 ran R c = A