Theorem isclo2 22239

Description: A set 𝐴 is clopen iff for every point 𝑥 in the space there is a neighborhood 𝑦 of 𝑥 which is either disjoint from 𝐴 or contained in 𝐴. (Contributed by Mario Carneiro, 7-Jul-2015.)

Hypothesis

Ref	Expression
isclo.1	⊢ 𝑋 = ∪ 𝐽

Assertion

Ref	Expression
isclo2	⊢ ((𝐽 ∈ Top ∧ 𝐴 ⊆ 𝑋) → (𝐴 ∈ (𝐽 ∩ (Clsd‘𝐽)) ↔ ∀𝑥 ∈ 𝑋 ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴))))

Distinct variable groups:   𝑥,𝑦,𝑧,𝐴   𝑥,𝐽,𝑦,𝑧   𝑥,𝑋,𝑦,𝑧

Proof of Theorem isclo2

Dummy variable 𝑤 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		isclo.1	. . 3 ⊢ 𝑋 = ∪ 𝐽
2	1	isclo 22238	. 2 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ⊆ 𝑋) → (𝐴 ∈ (𝐽 ∩ (Clsd‘𝐽)) ↔ ∀𝑥 ∈ 𝑋 ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴))))
3		eleq1w 2821	. . . . . . . . . . 11 ⊢ (𝑧 = 𝑤 → (𝑧 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴))
4	3	bibi2d 343	. . . . . . . . . 10 ⊢ (𝑧 = 𝑤 → ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)))
5	4	cbvralvw 3383	. . . . . . . . 9 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ ∀𝑤 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴))
6	5	anbi2i 623	. . . . . . . 8 ⊢ ((∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) ↔ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ ∀𝑤 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)))
7		pm4.24 564	. . . . . . . 8 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)))
8		raaanv 4452	. . . . . . . 8 ⊢ (∀𝑧 ∈ 𝑦 ∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) ↔ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ ∀𝑤 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)))
9	6, 7, 8	3bitr4i 303	. . . . . . 7 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ ∀𝑧 ∈ 𝑦 ∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)))
10		bibi1 352	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) → ((𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴) ↔ (𝑧 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)))
11	10	biimpa 477	. . . . . . . . . . . 12 ⊢ (((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → (𝑧 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴))
12	11	biimpcd 248	. . . . . . . . . . 11 ⊢ (𝑧 ∈ 𝐴 → (((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → 𝑤 ∈ 𝐴))
13	12	ralimdv 3109	. . . . . . . . . 10 ⊢ (𝑧 ∈ 𝐴 → (∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → ∀𝑤 ∈ 𝑦 𝑤 ∈ 𝐴))
14	13	com12 32	. . . . . . . . 9 ⊢ (∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → (𝑧 ∈ 𝐴 → ∀𝑤 ∈ 𝑦 𝑤 ∈ 𝐴))
15		dfss3 3909	. . . . . . . . 9 ⊢ (𝑦 ⊆ 𝐴 ↔ ∀𝑤 ∈ 𝑦 𝑤 ∈ 𝐴)
16	14, 15	syl6ibr 251	. . . . . . . 8 ⊢ (∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴))
17	16	ralimi 3087	. . . . . . 7 ⊢ (∀𝑧 ∈ 𝑦 ∀𝑤 ∈ 𝑦 ((𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ∧ (𝑥 ∈ 𝐴 ↔ 𝑤 ∈ 𝐴)) → ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴))
18	9, 17	sylbi 216	. . . . . 6 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) → ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴))
19		eleq1w 2821	. . . . . . . . . . 11 ⊢ (𝑧 = 𝑥 → (𝑧 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴))
20	19	imbi1d 342	. . . . . . . . . 10 ⊢ (𝑧 = 𝑥 → ((𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) ↔ (𝑥 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
21	20	rspcv 3557	. . . . . . . . 9 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → (𝑥 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
22		dfss3 3909	. . . . . . . . . . 11 ⊢ (𝑦 ⊆ 𝐴 ↔ ∀𝑧 ∈ 𝑦 𝑧 ∈ 𝐴)
23	22	imbi2i 336	. . . . . . . . . 10 ⊢ ((𝑥 ∈ 𝐴 → 𝑦 ⊆ 𝐴) ↔ (𝑥 ∈ 𝐴 → ∀𝑧 ∈ 𝑦 𝑧 ∈ 𝐴))
24		r19.21v 3113	. . . . . . . . . 10 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 → 𝑧 ∈ 𝐴) ↔ (𝑥 ∈ 𝐴 → ∀𝑧 ∈ 𝑦 𝑧 ∈ 𝐴))
25	23, 24	bitr4i 277	. . . . . . . . 9 ⊢ ((𝑥 ∈ 𝐴 → 𝑦 ⊆ 𝐴) ↔ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 → 𝑧 ∈ 𝐴))
26	21, 25	syl6ib 250	. . . . . . . 8 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 → 𝑧 ∈ 𝐴)))
27		ssel 3914	. . . . . . . . . . 11 ⊢ (𝑦 ⊆ 𝐴 → (𝑥 ∈ 𝑦 → 𝑥 ∈ 𝐴))
28	27	com12 32	. . . . . . . . . 10 ⊢ (𝑥 ∈ 𝑦 → (𝑦 ⊆ 𝐴 → 𝑥 ∈ 𝐴))
29	28	imim2d 57	. . . . . . . . 9 ⊢ (𝑥 ∈ 𝑦 → ((𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → (𝑧 ∈ 𝐴 → 𝑥 ∈ 𝐴)))
30	29	ralimdv 3109	. . . . . . . 8 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑥 ∈ 𝐴)))
31	26, 30	jcad 513	. . . . . . 7 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 → 𝑧 ∈ 𝐴) ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑥 ∈ 𝐴))))
32		ralbiim 3099	. . . . . . 7 ⊢ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 → 𝑧 ∈ 𝐴) ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑥 ∈ 𝐴)))
33	31, 32	syl6ibr 251	. . . . . 6 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴) → ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)))
34	18, 33	impbid2 225	. . . . 5 ⊢ (𝑥 ∈ 𝑦 → (∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴) ↔ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
35	34	pm5.32i 575	. . . 4 ⊢ ((𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) ↔ (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
36	35	rexbii 3181	. . 3 ⊢ (∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) ↔ ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
37	36	ralbii 3092	. 2 ⊢ (∀𝑥 ∈ 𝑋 ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑥 ∈ 𝐴 ↔ 𝑧 ∈ 𝐴)) ↔ ∀𝑥 ∈ 𝑋 ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴)))
38	2, 37	bitrdi 287	1 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ⊆ 𝑋) → (𝐴 ∈ (𝐽 ∩ (Clsd‘𝐽)) ↔ ∀𝑥 ∈ 𝑋 ∃𝑦 ∈ 𝐽 (𝑥 ∈ 𝑦 ∧ ∀𝑧 ∈ 𝑦 (𝑧 ∈ 𝐴 → 𝑦 ⊆ 𝐴))))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 396   = wceq 1539   ∈ wcel 2106  ∀wral 3064  ∃wrex 3065   ∩ cin 3886   ⊆ wss 3887  ∪ cuni 4839  ‘cfv 6433  Topctop 22042  Clsdccld 22167

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2709  ax-sep 5223  ax-nul 5230  ax-pow 5288  ax-pr 5352  ax-un 7588

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 845  df-3an 1088  df-tru 1542  df-fal 1552  df-ex 1783  df-nf 1787  df-sb 2068  df-mo 2540  df-eu 2569  df-clab 2716  df-cleq 2730  df-clel 2816  df-nfc 2889  df-ne 2944  df-ral 3069  df-rex 3070  df-rab 3073  df-v 3434  df-dif 3890  df-un 3892  df-in 3894  df-ss 3904  df-nul 4257  df-if 4460  df-pw 4535  df-sn 4562  df-pr 4564  df-op 4568  df-uni 4840  df-br 5075  df-opab 5137  df-mpt 5158  df-id 5489  df-xp 5595  df-rel 5596  df-cnv 5597  df-co 5598  df-dm 5599  df-iota 6391  df-fun 6435  df-fv 6441  df-topgen 17154  df-top 22043  df-cld 22170

This theorem is referenced by:  connpconn  33197