Theorem kqnrm 23600

Description: The Kolmogorov quotient of a normal space is normal. (Contributed by Mario Carneiro, 25-Aug-2015.)

Assertion

Ref	Expression
kqnrm	⊢ (𝐽 ∈ Nrm ↔ (KQ‘𝐽) ∈ Nrm)

Proof of Theorem kqnrm

Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		nrmtop 23184	. . . 4 ⊢ (𝐽 ∈ Nrm → 𝐽 ∈ Top)
2		toptopon2 22764	. . . 4 ⊢ (𝐽 ∈ Top ↔ 𝐽 ∈ (TopOn‘∪ 𝐽))
3	1, 2	sylib 217	. . 3 ⊢ (𝐽 ∈ Nrm → 𝐽 ∈ (TopOn‘∪ 𝐽))
4		eqid 2724	. . . 4 ⊢ (𝑥 ∈ ∪ 𝐽 ↦ {𝑦 ∈ 𝐽 ∣ 𝑥 ∈ 𝑦}) = (𝑥 ∈ ∪ 𝐽 ↦ {𝑦 ∈ 𝐽 ∣ 𝑥 ∈ 𝑦})
5	4	kqnrmlem1 23591	. . 3 ⊢ ((𝐽 ∈ (TopOn‘∪ 𝐽) ∧ 𝐽 ∈ Nrm) → (KQ‘𝐽) ∈ Nrm)
6	3, 5	mpancom 685	. 2 ⊢ (𝐽 ∈ Nrm → (KQ‘𝐽) ∈ Nrm)
7		nrmtop 23184	. . . . 5 ⊢ ((KQ‘𝐽) ∈ Nrm → (KQ‘𝐽) ∈ Top)
8		kqtop 23593	. . . . 5 ⊢ (𝐽 ∈ Top ↔ (KQ‘𝐽) ∈ Top)
9	7, 8	sylibr 233	. . . 4 ⊢ ((KQ‘𝐽) ∈ Nrm → 𝐽 ∈ Top)
10	9, 2	sylib 217	. . 3 ⊢ ((KQ‘𝐽) ∈ Nrm → 𝐽 ∈ (TopOn‘∪ 𝐽))
11	4	kqnrmlem2 23592	. . 3 ⊢ ((𝐽 ∈ (TopOn‘∪ 𝐽) ∧ (KQ‘𝐽) ∈ Nrm) → 𝐽 ∈ Nrm)
12	10, 11	mpancom 685	. 2 ⊢ ((KQ‘𝐽) ∈ Nrm → 𝐽 ∈ Nrm)
13	6, 12	impbii 208	1 ⊢ (𝐽 ∈ Nrm ↔ (KQ‘𝐽) ∈ Nrm)

Syntax hints:   ↔ wb 205   ∈ wcel 2098  {crab 3424  ∪ cuni 4900   ↦ cmpt 5222  ‘cfv 6534  Topctop 22739  TopOnctopon 22756  Nrmcnrm 23158  KQckq 23541

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1789  ax-4 1803  ax-5 1905  ax-6 1963  ax-7 2003  ax-8 2100  ax-9 2108  ax-10 2129  ax-11 2146  ax-12 2163  ax-ext 2695  ax-rep 5276  ax-sep 5290  ax-nul 5297  ax-pow 5354  ax-pr 5418  ax-un 7719

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 845  df-3an 1086  df-tru 1536  df-fal 1546  df-ex 1774  df-nf 1778  df-sb 2060  df-mo 2526  df-eu 2555  df-clab 2702  df-cleq 2716  df-clel 2802  df-nfc 2877  df-ne 2933  df-ral 3054  df-rex 3063  df-reu 3369  df-rab 3425  df-v 3468  df-sbc 3771  df-csb 3887  df-dif 3944  df-un 3946  df-in 3948  df-ss 3958  df-nul 4316  df-if 4522  df-pw 4597  df-sn 4622  df-pr 4624  df-op 4628  df-uni 4901  df-int 4942  df-iun 4990  df-iin 4991  df-br 5140  df-opab 5202  df-mpt 5223  df-id 5565  df-xp 5673  df-rel 5674  df-cnv 5675  df-co 5676  df-dm 5677  df-rn 5678  df-res 5679  df-ima 5680  df-iota 6486  df-fun 6536  df-fn 6537  df-f 6538  df-f1 6539  df-fo 6540  df-f1o 6541  df-fv 6542  df-ov 7405  df-oprab 7406  df-mpo 7407  df-map 8819  df-qtop 17458  df-top 22740  df-topon 22757  df-cld 22867  df-cls 22869  df-cn 23075  df-nrm 23165  df-kq 23542

This theorem is referenced by: (None)