Metamath Proof Explorer


Theorem flimsncls

Description: If A is a limit point of the filter F , then all the points which specialize A (in the specialization preorder) are also limit points. Thus, the set of limit points is a union of closed sets (although this is only nontrivial for non-T1 spaces). (Contributed by Mario Carneiro, 20-Sep-2015)

Ref Expression
Assertion flimsncls ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ⊆ ( 𝐽 fLim 𝐹 ) )

Proof

Step Hyp Ref Expression
1 flimtop ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → 𝐽 ∈ Top )
2 eqid 𝐽 = 𝐽
3 2 flimelbas ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → 𝐴 𝐽 )
4 3 snssd ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → { 𝐴 } ⊆ 𝐽 )
5 2 clsss3 ( ( 𝐽 ∈ Top ∧ { 𝐴 } ⊆ 𝐽 ) → ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ⊆ 𝐽 )
6 1 4 5 syl2anc ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ⊆ 𝐽 )
7 6 sselda ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝑥 𝐽 )
8 simpll ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝐴 ∈ ( 𝐽 fLim 𝐹 ) )
9 8 1 syl ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝐽 ∈ Top )
10 simprl ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝑦𝐽 )
11 1 adantr ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝐽 ∈ Top )
12 4 adantr ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → { 𝐴 } ⊆ 𝐽 )
13 simpr ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) )
14 11 12 13 3jca ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → ( 𝐽 ∈ Top ∧ { 𝐴 } ⊆ 𝐽𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) )
15 2 clsndisj ( ( ( 𝐽 ∈ Top ∧ { 𝐴 } ⊆ 𝐽𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → ( 𝑦 ∩ { 𝐴 } ) ≠ ∅ )
16 disjsn ( ( 𝑦 ∩ { 𝐴 } ) = ∅ ↔ ¬ 𝐴𝑦 )
17 16 necon2abii ( 𝐴𝑦 ↔ ( 𝑦 ∩ { 𝐴 } ) ≠ ∅ )
18 15 17 sylibr ( ( ( 𝐽 ∈ Top ∧ { 𝐴 } ⊆ 𝐽𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝐴𝑦 )
19 14 18 sylan ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝐴𝑦 )
20 opnneip ( ( 𝐽 ∈ Top ∧ 𝑦𝐽𝐴𝑦 ) → 𝑦 ∈ ( ( nei ‘ 𝐽 ) ‘ { 𝐴 } ) )
21 9 10 19 20 syl3anc ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝑦 ∈ ( ( nei ‘ 𝐽 ) ‘ { 𝐴 } ) )
22 flimnei ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑦 ∈ ( ( nei ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝑦𝐹 )
23 8 21 22 syl2anc ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ ( 𝑦𝐽𝑥𝑦 ) ) → 𝑦𝐹 )
24 23 expr ( ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) ∧ 𝑦𝐽 ) → ( 𝑥𝑦𝑦𝐹 ) )
25 24 ralrimiva ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → ∀ 𝑦𝐽 ( 𝑥𝑦𝑦𝐹 ) )
26 toptopon2 ( 𝐽 ∈ Top ↔ 𝐽 ∈ ( TopOn ‘ 𝐽 ) )
27 11 26 sylib ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝐽 ∈ ( TopOn ‘ 𝐽 ) )
28 2 flimfil ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → 𝐹 ∈ ( Fil ‘ 𝐽 ) )
29 28 adantr ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝐹 ∈ ( Fil ‘ 𝐽 ) )
30 flimopn ( ( 𝐽 ∈ ( TopOn ‘ 𝐽 ) ∧ 𝐹 ∈ ( Fil ‘ 𝐽 ) ) → ( 𝑥 ∈ ( 𝐽 fLim 𝐹 ) ↔ ( 𝑥 𝐽 ∧ ∀ 𝑦𝐽 ( 𝑥𝑦𝑦𝐹 ) ) ) )
31 27 29 30 syl2anc ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → ( 𝑥 ∈ ( 𝐽 fLim 𝐹 ) ↔ ( 𝑥 𝐽 ∧ ∀ 𝑦𝐽 ( 𝑥𝑦𝑦𝐹 ) ) ) )
32 7 25 31 mpbir2and ( ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) ∧ 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ) → 𝑥 ∈ ( 𝐽 fLim 𝐹 ) )
33 32 ex ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → ( 𝑥 ∈ ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) → 𝑥 ∈ ( 𝐽 fLim 𝐹 ) ) )
34 33 ssrdv ( 𝐴 ∈ ( 𝐽 fLim 𝐹 ) → ( ( cls ‘ 𝐽 ) ‘ { 𝐴 } ) ⊆ ( 𝐽 fLim 𝐹 ) )