Theorem mreiincl 17641

Description: A nonempty indexed intersection of closed sets is closed. (Contributed by Stefan O'Rear, 1-Feb-2015.)

Assertion

Ref	Expression
mreiincl	⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → ∩ 𝑦 ∈ 𝐼 𝑆 ∈ 𝐶)

Distinct variable groups:   𝑦,𝐼   𝑦,𝑋   𝑦,𝐶

Allowed substitution hint:   𝑆(𝑦)

Proof of Theorem mreiincl

Dummy variable 𝑠 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		dfiin2g 5037	. . 3 ⊢ (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → ∩ 𝑦 ∈ 𝐼 𝑆 = ∩ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆})
2	1	3ad2ant3 1134	. 2 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → ∩ 𝑦 ∈ 𝐼 𝑆 = ∩ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆})
3		simp1 1135	. . 3 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → 𝐶 ∈ (Moore‘𝑋))
4		uniiunlem 4097	. . . . 5 ⊢ (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 ↔ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ⊆ 𝐶))
5	4	ibi 267	. . . 4 ⊢ (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ⊆ 𝐶)
6	5	3ad2ant3 1134	. . 3 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ⊆ 𝐶)
7		n0 4359	. . . . . 6 ⊢ (𝐼 ≠ ∅ ↔ ∃𝑦 𝑦 ∈ 𝐼)
8		nfra1 3282	. . . . . . . 8 ⊢ Ⅎ𝑦∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶
9		nfre1 3283	. . . . . . . . . 10 ⊢ Ⅎ𝑦∃𝑦 ∈ 𝐼 𝑠 = 𝑆
10	9	nfab 2909	. . . . . . . . 9 ⊢ Ⅎ𝑦{𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆}
11		nfcv 2903	. . . . . . . . 9 ⊢ Ⅎ𝑦∅
12	10, 11	nfne 3041	. . . . . . . 8 ⊢ Ⅎ𝑦{𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅
13	8, 12	nfim 1894	. . . . . . 7 ⊢ Ⅎ𝑦(∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅)
14		rsp 3245	. . . . . . . . . 10 ⊢ (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → (𝑦 ∈ 𝐼 → 𝑆 ∈ 𝐶))
15	14	com12 32	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐼 → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → 𝑆 ∈ 𝐶))
16		elisset 2821	. . . . . . . . . . 11 ⊢ (𝑆 ∈ 𝐶 → ∃𝑠 𝑠 = 𝑆)
17		rspe 3247	. . . . . . . . . . . 12 ⊢ ((𝑦 ∈ 𝐼 ∧ ∃𝑠 𝑠 = 𝑆) → ∃𝑦 ∈ 𝐼 ∃𝑠 𝑠 = 𝑆)
18	17	ex 412	. . . . . . . . . . 11 ⊢ (𝑦 ∈ 𝐼 → (∃𝑠 𝑠 = 𝑆 → ∃𝑦 ∈ 𝐼 ∃𝑠 𝑠 = 𝑆))
19	16, 18	syl5 34	. . . . . . . . . 10 ⊢ (𝑦 ∈ 𝐼 → (𝑆 ∈ 𝐶 → ∃𝑦 ∈ 𝐼 ∃𝑠 𝑠 = 𝑆))
20		rexcom4 3286	. . . . . . . . . 10 ⊢ (∃𝑦 ∈ 𝐼 ∃𝑠 𝑠 = 𝑆 ↔ ∃𝑠∃𝑦 ∈ 𝐼 𝑠 = 𝑆)
21	19, 20	imbitrdi 251	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐼 → (𝑆 ∈ 𝐶 → ∃𝑠∃𝑦 ∈ 𝐼 𝑠 = 𝑆))
22	15, 21	syld 47	. . . . . . . 8 ⊢ (𝑦 ∈ 𝐼 → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → ∃𝑠∃𝑦 ∈ 𝐼 𝑠 = 𝑆))
23		abn0 4391	. . . . . . . 8 ⊢ ({𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅ ↔ ∃𝑠∃𝑦 ∈ 𝐼 𝑠 = 𝑆)
24	22, 23	imbitrrdi 252	. . . . . . 7 ⊢ (𝑦 ∈ 𝐼 → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅))
25	13, 24	exlimi 2215	. . . . . 6 ⊢ (∃𝑦 𝑦 ∈ 𝐼 → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅))
26	7, 25	sylbi 217	. . . . 5 ⊢ (𝐼 ≠ ∅ → (∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶 → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅))
27	26	imp 406	. . . 4 ⊢ ((𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅)
28	27	3adant1 1129	. . 3 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅)
29		mreintcl 17640	. . 3 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ⊆ 𝐶 ∧ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ≠ ∅) → ∩ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ∈ 𝐶)
30	3, 6, 28, 29	syl3anc 1370	. 2 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → ∩ {𝑠 ∣ ∃𝑦 ∈ 𝐼 𝑠 = 𝑆} ∈ 𝐶)
31	2, 30	eqeltrd 2839	1 ⊢ ((𝐶 ∈ (Moore‘𝑋) ∧ 𝐼 ≠ ∅ ∧ ∀𝑦 ∈ 𝐼 𝑆 ∈ 𝐶) → ∩ 𝑦 ∈ 𝐼 𝑆 ∈ 𝐶)

Syntax hints:   → wi 4   ∧ w3a 1086   = wceq 1537  ∃wex 1776   ∈ wcel 2106  {cab 2712   ≠ wne 2938  ∀wral 3059  ∃wrex 3068   ⊆ wss 3963  ∅c0 4339  ∩ cint 4951  ∩ ciin 4997  ‘cfv 6563  Moorecmre 17627

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-8 2108  ax-9 2116  ax-10 2139  ax-11 2155  ax-12 2175  ax-ext 2706  ax-sep 5302  ax-nul 5312  ax-pow 5371  ax-pr 5438

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1540  df-fal 1550  df-ex 1777  df-nf 1781  df-sb 2063  df-mo 2538  df-eu 2567  df-clab 2713  df-cleq 2727  df-clel 2814  df-nfc 2890  df-ne 2939  df-ral 3060  df-rex 3069  df-rab 3434  df-v 3480  df-dif 3966  df-un 3968  df-in 3970  df-ss 3980  df-nul 4340  df-if 4532  df-pw 4607  df-sn 4632  df-pr 4634  df-op 4638  df-uni 4913  df-int 4952  df-iin 4999  df-br 5149  df-opab 5211  df-mpt 5232  df-id 5583  df-xp 5695  df-rel 5696  df-cnv 5697  df-co 5698  df-dm 5699  df-iota 6516  df-fun 6565  df-fv 6571  df-mre 17631

This theorem is referenced by:  mreriincl  17643  mretopd  23116