Theorem hmphindis 23787

Description: Homeomorphisms preserve topological indiscreteness. (Contributed by FL, 18-Aug-2008.) (Revised by Mario Carneiro, 10-Sep-2015.)

Hypothesis

Ref	Expression
hmphdis.1	⊢ 𝑋 = ∪ 𝐽

Assertion

Ref	Expression
hmphindis	⊢ (𝐽 ≃ {∅, 𝐴} → 𝐽 = {∅, 𝑋})

Proof of Theorem hmphindis

Step	Hyp	Ref	Expression
1		dfsn2 4575	. . 3 ⊢ {∅} = {∅, ∅}
2		indislem 22990	. . . . . . 7 ⊢ {∅, ( I ‘𝐴)} = {∅, 𝐴}
3		preq2 4673	. . . . . . . 8 ⊢ (( I ‘𝐴) = ∅ → {∅, ( I ‘𝐴)} = {∅, ∅})
4	3, 1	eqtr4di 2793	. . . . . . 7 ⊢ (( I ‘𝐴) = ∅ → {∅, ( I ‘𝐴)} = {∅})
5	2, 4	eqtr3id 2789	. . . . . 6 ⊢ (( I ‘𝐴) = ∅ → {∅, 𝐴} = {∅})
6	5	breq2d 5091	. . . . 5 ⊢ (( I ‘𝐴) = ∅ → (𝐽 ≃ {∅, 𝐴} ↔ 𝐽 ≃ {∅}))
7	6	biimpac 479	. . . 4 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → 𝐽 ≃ {∅})
8		hmph0 23785	. . . 4 ⊢ (𝐽 ≃ {∅} ↔ 𝐽 = {∅})
9	7, 8	sylib 219	. . 3 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → 𝐽 = {∅})
10	9	unieqd 4858	. . . . 5 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → ∪ 𝐽 = ∪ {∅})
11		hmphdis.1	. . . . 5 ⊢ 𝑋 = ∪ 𝐽
12		0ex 5236	. . . . . . 7 ⊢ ∅ ∈ V
13	12	unisn 4864	. . . . . 6 ⊢ ∪ {∅} = ∅
14	13	eqcomi 2749	. . . . 5 ⊢ ∅ = ∪ {∅}
15	10, 11, 14	3eqtr4g 2800	. . . 4 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → 𝑋 = ∅)
16	15	preq2d 4679	. . 3 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → {∅, 𝑋} = {∅, ∅})
17	1, 9, 16	3eqtr4a 2801	. 2 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) = ∅) → 𝐽 = {∅, 𝑋})
18		hmphen 23775	. . . . 5 ⊢ (𝐽 ≃ {∅, 𝐴} → 𝐽 ≈ {∅, 𝐴})
19		necom 2988	. . . . . . . 8 ⊢ (( I ‘𝐴) ≠ ∅ ↔ ∅ ≠ ( I ‘𝐴))
20		fvex 6847	. . . . . . . . 9 ⊢ ( I ‘𝐴) ∈ V
21		enpr2 9924	. . . . . . . . 9 ⊢ ((∅ ∈ V ∧ ( I ‘𝐴) ∈ V ∧ ∅ ≠ ( I ‘𝐴)) → {∅, ( I ‘𝐴)} ≈ 2o)
22	12, 20, 21	mp3an12 1459	. . . . . . . 8 ⊢ (∅ ≠ ( I ‘𝐴) → {∅, ( I ‘𝐴)} ≈ 2o)
23	19, 22	sylbi 218	. . . . . . 7 ⊢ (( I ‘𝐴) ≠ ∅ → {∅, ( I ‘𝐴)} ≈ 2o)
24	23	adantl 482	. . . . . 6 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → {∅, ( I ‘𝐴)} ≈ 2o)
25	2, 24	eqbrtrrid 5115	. . . . 5 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → {∅, 𝐴} ≈ 2o)
26		entr 8950	. . . . 5 ⊢ ((𝐽 ≈ {∅, 𝐴} ∧ {∅, 𝐴} ≈ 2o) → 𝐽 ≈ 2o)
27	18, 25, 26	syl2an2r 691	. . . 4 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → 𝐽 ≈ 2o)
28		hmphtop1 23769	. . . . . . 7 ⊢ (𝐽 ≃ {∅, 𝐴} → 𝐽 ∈ Top)
29	28	adantr 481	. . . . . 6 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → 𝐽 ∈ Top)
30	11	toptopon 22907	. . . . . 6 ⊢ (𝐽 ∈ Top ↔ 𝐽 ∈ (TopOn‘𝑋))
31	29, 30	sylib 219	. . . . 5 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → 𝐽 ∈ (TopOn‘𝑋))
32		en2top 22975	. . . . 5 ⊢ (𝐽 ∈ (TopOn‘𝑋) → (𝐽 ≈ 2o ↔ (𝐽 = {∅, 𝑋} ∧ 𝑋 ≠ ∅)))
33	31, 32	syl 17	. . . 4 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → (𝐽 ≈ 2o ↔ (𝐽 = {∅, 𝑋} ∧ 𝑋 ≠ ∅)))
34	27, 33	mpbid 233	. . 3 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → (𝐽 = {∅, 𝑋} ∧ 𝑋 ≠ ∅))
35	34	simpld 495	. 2 ⊢ ((𝐽 ≃ {∅, 𝐴} ∧ ( I ‘𝐴) ≠ ∅) → 𝐽 = {∅, 𝑋})
36	17, 35	pm2.61dane 3022	1 ⊢ (𝐽 ≃ {∅, 𝐴} → 𝐽 = {∅, 𝑋})

Syntax hints:   → wi 4   ↔ wb 207   ∧ wa 396   = wceq 1547   ∈ wcel 2119   ≠ wne 2935  Vcvv 3432  ∅c0 4268  {csn 4562  {cpr 4564  ∪ cuni 4845   class class class wbr 5079   I cid 5519  ‘cfv 6492  2_oc2o 8396   ≈ cen 8887  Topctop 22883  TopOnctopon 22900   ≃ chmph 23744

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1802  ax-4 1816  ax-5 1917  ax-6 1974  ax-7 2015  ax-8 2121  ax-9 2129  ax-10 2152  ax-11 2168  ax-12 2189  ax-ext 2712  ax-sep 5225  ax-nul 5235  ax-pow 5301  ax-pr 5369  ax-un 7685

This theorem depends on definitions:  df-bi 208  df-an 397  df-or 854  df-3or 1093  df-3an 1094  df-tru 1550  df-fal 1560  df-ex 1787  df-nf 1791  df-sb 2074  df-mo 2543  df-eu 2573  df-clab 2719  df-cleq 2732  df-clel 2815  df-nfc 2889  df-ne 2936  df-ral 3055  df-rex 3065  df-reu 3346  df-rab 3393  df-v 3434  df-sbc 3731  df-csb 3839  df-dif 3893  df-un 3895  df-in 3897  df-ss 3907  df-pss 3910  df-nul 4269  df-if 4462  df-pw 4538  df-sn 4563  df-pr 4565  df-op 4569  df-uni 4846  df-int 4885  df-iun 4930  df-br 5080  df-opab 5142  df-mpt 5161  df-tr 5187  df-id 5520  df-eprel 5525  df-po 5533  df-so 5534  df-fr 5578  df-we 5580  df-xp 5631  df-rel 5632  df-cnv 5633  df-co 5634  df-dm 5635  df-rn 5636  df-res 5637  df-ima 5638  df-ord 6320  df-on 6321  df-lim 6322  df-suc 6323  df-iota 6448  df-fun 6494  df-fn 6495  df-f 6496  df-f1 6497  df-fo 6498  df-f1o 6499  df-fv 6500  df-ov 7366  df-oprab 7367  df-mpo 7368  df-om 7814  df-1st 7938  df-2nd 7939  df-1o 8402  df-2o 8403  df-er 8640  df-map 8772  df-en 8891  df-dom 8892  df-sdom 8893  df-fin 8894  df-card 9861  df-top 22884  df-topon 22901  df-cn 23217  df-hmeo 23745  df-hmph 23746

This theorem is referenced by: (None)