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Theorem cmpcov 21240
 Description: An open cover of a compact topology has a finite subcover. (Contributed by Jeff Hankins, 29-Jun-2009.)
Hypothesis
Ref Expression
iscmp.1 𝑋 = 𝐽
Assertion
Ref Expression
cmpcov ((𝐽 ∈ Comp ∧ 𝑆𝐽𝑋 = 𝑆) → ∃𝑠 ∈ (𝒫 𝑆 ∩ Fin)𝑋 = 𝑠)
Distinct variable groups:   𝐽,𝑠   𝑆,𝑠
Allowed substitution hint:   𝑋(𝑠)

Proof of Theorem cmpcov
Dummy variable 𝑟 is distinct from all other variables.
StepHypRef Expression
1 unieq 4476 . . . . 5 (𝑟 = 𝑆 𝑟 = 𝑆)
21eqeq2d 2661 . . . 4 (𝑟 = 𝑆 → (𝑋 = 𝑟𝑋 = 𝑆))
3 pweq 4194 . . . . . 6 (𝑟 = 𝑆 → 𝒫 𝑟 = 𝒫 𝑆)
43ineq1d 3846 . . . . 5 (𝑟 = 𝑆 → (𝒫 𝑟 ∩ Fin) = (𝒫 𝑆 ∩ Fin))
54rexeqdv 3175 . . . 4 (𝑟 = 𝑆 → (∃𝑠 ∈ (𝒫 𝑟 ∩ Fin)𝑋 = 𝑠 ↔ ∃𝑠 ∈ (𝒫 𝑆 ∩ Fin)𝑋 = 𝑠))
62, 5imbi12d 333 . . 3 (𝑟 = 𝑆 → ((𝑋 = 𝑟 → ∃𝑠 ∈ (𝒫 𝑟 ∩ Fin)𝑋 = 𝑠) ↔ (𝑋 = 𝑆 → ∃𝑠 ∈ (𝒫 𝑆 ∩ Fin)𝑋 = 𝑠)))
7 iscmp.1 . . . . . 6 𝑋 = 𝐽
87iscmp 21239 . . . . 5 (𝐽 ∈ Comp ↔ (𝐽 ∈ Top ∧ ∀𝑟 ∈ 𝒫 𝐽(𝑋 = 𝑟 → ∃𝑠 ∈ (𝒫 𝑟 ∩ Fin)𝑋 = 𝑠)))
98simprbi 479 . . . 4 (𝐽 ∈ Comp → ∀𝑟 ∈ 𝒫 𝐽(𝑋 = 𝑟 → ∃𝑠 ∈ (𝒫 𝑟 ∩ Fin)𝑋 = 𝑠))
109adantr 480 . . 3 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → ∀𝑟 ∈ 𝒫 𝐽(𝑋 = 𝑟 → ∃𝑠 ∈ (𝒫 𝑟 ∩ Fin)𝑋 = 𝑠))
11 simpr 476 . . . 4 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → 𝑆𝐽)
12 ssexg 4837 . . . . . 6 ((𝑆𝐽𝐽 ∈ Comp) → 𝑆 ∈ V)
1312ancoms 468 . . . . 5 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → 𝑆 ∈ V)
14 elpwg 4199 . . . . 5 (𝑆 ∈ V → (𝑆 ∈ 𝒫 𝐽𝑆𝐽))
1513, 14syl 17 . . . 4 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → (𝑆 ∈ 𝒫 𝐽𝑆𝐽))
1611, 15mpbird 247 . . 3 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → 𝑆 ∈ 𝒫 𝐽)
176, 10, 16rspcdva 3347 . 2 ((𝐽 ∈ Comp ∧ 𝑆𝐽) → (𝑋 = 𝑆 → ∃𝑠 ∈ (𝒫 𝑆 ∩ Fin)𝑋 = 𝑠))
18173impia 1280 1 ((𝐽 ∈ Comp ∧ 𝑆𝐽𝑋 = 𝑆) → ∃𝑠 ∈ (𝒫 𝑆 ∩ Fin)𝑋 = 𝑠)
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 196   ∧ wa 383   ∧ w3a 1054   = wceq 1523   ∈ wcel 2030  ∀wral 2941  ∃wrex 2942  Vcvv 3231   ∩ cin 3606   ⊆ wss 3607  𝒫 cpw 4191  ∪ cuni 4468  Fincfn 7997  Topctop 20746  Compccmp 21237 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1762  ax-4 1777  ax-5 1879  ax-6 1945  ax-7 1981  ax-9 2039  ax-10 2059  ax-11 2074  ax-12 2087  ax-13 2282  ax-ext 2631  ax-sep 4814 This theorem depends on definitions:  df-bi 197  df-or 384  df-an 385  df-3an 1056  df-tru 1526  df-ex 1745  df-nf 1750  df-sb 1938  df-clab 2638  df-cleq 2644  df-clel 2647  df-nfc 2782  df-ral 2946  df-rex 2947  df-rab 2950  df-v 3233  df-in 3614  df-ss 3621  df-pw 4193  df-uni 4469  df-cmp 21238 This theorem is referenced by:  cmpcov2  21241  cncmp  21243  discmp  21249  cmpcld  21253  sscmp  21256  comppfsc  21383  alexsubALTlem1  21898  ptcmplem3  21905  lebnum  22810  heibor1  33739
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