Metamath Proof Explorer


Theorem neibastop3

Description: The topology generated by a neighborhood base is unique. (Contributed by Jeff Hankins, 16-Sep-2009) (Proof shortened by Mario Carneiro, 11-Sep-2015)

Ref Expression
Hypotheses neibastop1.1 ( 𝜑𝑋𝑉 )
neibastop1.2 ( 𝜑𝐹 : 𝑋 ⟶ ( 𝒫 𝒫 𝑋 ∖ { ∅ } ) )
neibastop1.3 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ∧ 𝑤 ∈ ( 𝐹𝑥 ) ) ) → ( ( 𝐹𝑥 ) ∩ 𝒫 ( 𝑣𝑤 ) ) ≠ ∅ )
neibastop1.4 𝐽 = { 𝑜 ∈ 𝒫 𝑋 ∣ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ }
neibastop1.5 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ) ) → 𝑥𝑣 )
neibastop1.6 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ) ) → ∃ 𝑡 ∈ ( 𝐹𝑥 ) ∀ 𝑦𝑡 ( ( 𝐹𝑦 ) ∩ 𝒫 𝑣 ) ≠ ∅ )
Assertion neibastop3 ( 𝜑 → ∃! 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )

Proof

Step Hyp Ref Expression
1 neibastop1.1 ( 𝜑𝑋𝑉 )
2 neibastop1.2 ( 𝜑𝐹 : 𝑋 ⟶ ( 𝒫 𝒫 𝑋 ∖ { ∅ } ) )
3 neibastop1.3 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ∧ 𝑤 ∈ ( 𝐹𝑥 ) ) ) → ( ( 𝐹𝑥 ) ∩ 𝒫 ( 𝑣𝑤 ) ) ≠ ∅ )
4 neibastop1.4 𝐽 = { 𝑜 ∈ 𝒫 𝑋 ∣ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ }
5 neibastop1.5 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ) ) → 𝑥𝑣 )
6 neibastop1.6 ( ( 𝜑 ∧ ( 𝑥𝑋𝑣 ∈ ( 𝐹𝑥 ) ) ) → ∃ 𝑡 ∈ ( 𝐹𝑥 ) ∀ 𝑦𝑡 ( ( 𝐹𝑦 ) ∩ 𝒫 𝑣 ) ≠ ∅ )
7 1 2 3 4 neibastop1 ( 𝜑𝐽 ∈ ( TopOn ‘ 𝑋 ) )
8 1 2 3 4 5 6 neibastop2 ( ( 𝜑𝑧𝑋 ) → ( 𝑛 ∈ ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) ↔ ( 𝑛𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) ) )
9 velpw ( 𝑛 ∈ 𝒫 𝑋𝑛𝑋 )
10 9 anbi1i ( ( 𝑛 ∈ 𝒫 𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) ↔ ( 𝑛𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) )
11 8 10 bitr4di ( ( 𝜑𝑧𝑋 ) → ( 𝑛 ∈ ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) ↔ ( 𝑛 ∈ 𝒫 𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) ) )
12 11 abbi2dv ( ( 𝜑𝑧𝑋 ) → ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) = { 𝑛 ∣ ( 𝑛 ∈ 𝒫 𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) } )
13 df-rab { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } = { 𝑛 ∣ ( 𝑛 ∈ 𝒫 𝑋 ∧ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) }
14 12 13 eqtr4di ( ( 𝜑𝑧𝑋 ) → ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
15 14 ralrimiva ( 𝜑 → ∀ 𝑧𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
16 sneq ( 𝑥 = 𝑧 → { 𝑥 } = { 𝑧 } )
17 16 fveq2d ( 𝑥 = 𝑧 → ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) )
18 fveq2 ( 𝑥 = 𝑧 → ( 𝐹𝑥 ) = ( 𝐹𝑧 ) )
19 18 ineq1d ( 𝑥 = 𝑧 → ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) = ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) )
20 19 neeq1d ( 𝑥 = 𝑧 → ( ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ ↔ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ ) )
21 20 rabbidv ( 𝑥 = 𝑧 → { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
22 17 21 eqeq12d ( 𝑥 = 𝑧 → ( ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
23 22 cbvralvw ( ∀ 𝑥𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ∀ 𝑧𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑧 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑧 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
24 15 23 sylibr ( 𝜑 → ∀ 𝑥𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
25 toponuni ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) → 𝑋 = 𝑗 )
26 eqimss2 ( 𝑋 = 𝑗 𝑗𝑋 )
27 25 26 syl ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) → 𝑗𝑋 )
28 sspwuni ( 𝑗 ⊆ 𝒫 𝑋 𝑗𝑋 )
29 27 28 sylibr ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) → 𝑗 ⊆ 𝒫 𝑋 )
30 29 ad2antlr ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → 𝑗 ⊆ 𝒫 𝑋 )
31 sseqin2 ( 𝑗 ⊆ 𝒫 𝑋 ↔ ( 𝒫 𝑋𝑗 ) = 𝑗 )
32 30 31 sylib ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → ( 𝒫 𝑋𝑗 ) = 𝑗 )
33 topontop ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) → 𝑗 ∈ Top )
34 33 ad3antlr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → 𝑗 ∈ Top )
35 eltop2 ( 𝑗 ∈ Top → ( 𝑜𝑗 ↔ ∀ 𝑥𝑜𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ) )
36 34 35 syl ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( 𝑜𝑗 ↔ ∀ 𝑥𝑜𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ) )
37 elpwi ( 𝑜 ∈ 𝒫 𝑋𝑜𝑋 )
38 ssralv ( 𝑜𝑋 → ( ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ∀ 𝑥𝑜 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
39 37 38 syl ( 𝑜 ∈ 𝒫 𝑋 → ( ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ∀ 𝑥𝑜 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
40 39 adantl ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ∀ 𝑥𝑜 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
41 simprr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )
42 41 eleq2d ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → ( 𝑜 ∈ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) ↔ 𝑜 ∈ { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
43 33 ad3antlr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → 𝑗 ∈ Top )
44 25 adantl ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) → 𝑋 = 𝑗 )
45 44 sseq2d ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) → ( 𝑜𝑋𝑜 𝑗 ) )
46 45 biimpa ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜𝑋 ) → 𝑜 𝑗 )
47 37 46 sylan2 ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → 𝑜 𝑗 )
48 47 sselda ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ 𝑥𝑜 ) → 𝑥 𝑗 )
49 48 adantrr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → 𝑥 𝑗 )
50 47 adantr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → 𝑜 𝑗 )
51 eqid 𝑗 = 𝑗
52 51 isneip ( ( 𝑗 ∈ Top ∧ 𝑥 𝑗 ) → ( 𝑜 ∈ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) ↔ ( 𝑜 𝑗 ∧ ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ) ) )
53 52 baibd ( ( ( 𝑗 ∈ Top ∧ 𝑥 𝑗 ) ∧ 𝑜 𝑗 ) → ( 𝑜 ∈ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) ↔ ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ) )
54 43 49 50 53 syl21anc ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → ( 𝑜 ∈ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) ↔ ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ) )
55 pweq ( 𝑛 = 𝑜 → 𝒫 𝑛 = 𝒫 𝑜 )
56 55 ineq2d ( 𝑛 = 𝑜 → ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) = ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) )
57 56 neeq1d ( 𝑛 = 𝑜 → ( ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
58 57 elrab3 ( 𝑜 ∈ 𝒫 𝑋 → ( 𝑜 ∈ { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
59 58 ad2antlr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → ( 𝑜 ∈ { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
60 42 54 59 3bitr3d ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ( 𝑥𝑜 ∧ ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) → ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
61 60 expr ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ 𝑥𝑜 ) → ( ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) ) )
62 61 ralimdva ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( ∀ 𝑥𝑜 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ∀ 𝑥𝑜 ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) ) )
63 40 62 syld ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } → ∀ 𝑥𝑜 ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) ) )
64 63 imp ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ 𝑜 ∈ 𝒫 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → ∀ 𝑥𝑜 ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
65 64 an32s ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ∀ 𝑥𝑜 ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
66 ralbi ( ∀ 𝑥𝑜 ( ∃ 𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) → ( ∀ 𝑥𝑜𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
67 65 66 syl ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( ∀ 𝑥𝑜𝑧𝑗 ( 𝑥𝑧𝑧𝑜 ) ↔ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
68 36 67 bitrd ( ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ 𝑜 ∈ 𝒫 𝑋 ) → ( 𝑜𝑗 ↔ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ ) )
69 68 rabbi2dva ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → ( 𝒫 𝑋𝑗 ) = { 𝑜 ∈ 𝒫 𝑋 ∣ ∀ 𝑥𝑜 ( ( 𝐹𝑥 ) ∩ 𝒫 𝑜 ) ≠ ∅ } )
70 69 4 eqtr4di ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → ( 𝒫 𝑋𝑗 ) = 𝐽 )
71 32 70 eqtr3d ( ( ( 𝜑𝑗 ∈ ( TopOn ‘ 𝑋 ) ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → 𝑗 = 𝐽 )
72 71 expl ( 𝜑 → ( ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → 𝑗 = 𝐽 ) )
73 72 alrimiv ( 𝜑 → ∀ 𝑗 ( ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → 𝑗 = 𝐽 ) )
74 eleq1 ( 𝑗 = 𝐽 → ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ↔ 𝐽 ∈ ( TopOn ‘ 𝑋 ) ) )
75 fveq2 ( 𝑗 = 𝐽 → ( nei ‘ 𝑗 ) = ( nei ‘ 𝐽 ) )
76 75 fveq1d ( 𝑗 = 𝐽 → ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) )
77 76 eqeq1d ( 𝑗 = 𝐽 → ( ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
78 77 ralbidv ( 𝑗 = 𝐽 → ( ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ∀ 𝑥𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
79 74 78 anbi12d ( 𝑗 = 𝐽 → ( ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ↔ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ) )
80 79 eqeu ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝐽 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) ∧ ∀ 𝑗 ( ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) → 𝑗 = 𝐽 ) ) → ∃! 𝑗 ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
81 7 7 24 73 80 syl121anc ( 𝜑 → ∃! 𝑗 ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
82 df-reu ( ∃! 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ↔ ∃! 𝑗 ( 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∧ ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } ) )
83 81 82 sylibr ( 𝜑 → ∃! 𝑗 ∈ ( TopOn ‘ 𝑋 ) ∀ 𝑥𝑋 ( ( nei ‘ 𝑗 ) ‘ { 𝑥 } ) = { 𝑛 ∈ 𝒫 𝑋 ∣ ( ( 𝐹𝑥 ) ∩ 𝒫 𝑛 ) ≠ ∅ } )