Metamath Proof Explorer


Theorem maxlp

Description: A point is a limit point of the whole space iff the singleton of the point is not open. (Contributed by Mario Carneiro, 24-Dec-2016)

Ref Expression
Hypothesis lpfval.1 ⊢ X = ⋃ J
Assertion maxlp ⊢ J ∈ Top → P ∈ limPt ⁡ J ⁡ X ↔ P ∈ X ∧ ¬ P ∈ J

Proof

Step Hyp Ref Expression
1 lpfval.1 ⊢ X = ⋃ J
2 ssid ⊢ X ⊆ X
3 1 lpss ⊢ J ∈ Top ∧ X ⊆ X → limPt ⁡ J ⁡ X ⊆ X
4 2 3 mpan2 ⊢ J ∈ Top → limPt ⁡ J ⁡ X ⊆ X
5 4 sseld ⊢ J ∈ Top → P ∈ limPt ⁡ J ⁡ X → P ∈ X
6 5 pm4.71rd ⊢ J ∈ Top → P ∈ limPt ⁡ J ⁡ X ↔ P ∈ X ∧ P ∈ limPt ⁡ J ⁡ X
7 simpl ⊢ J ∈ Top ∧ P ∈ X → J ∈ Top
8 1 islp ⊢ J ∈ Top ∧ X ⊆ X → P ∈ limPt ⁡ J ⁡ X ↔ P ∈ cls ⁡ J ⁡ X ∖ P
9 7 2 8 sylancl ⊢ J ∈ Top ∧ P ∈ X → P ∈ limPt ⁡ J ⁡ X ↔ P ∈ cls ⁡ J ⁡ X ∖ P
10 snssi ⊢ P ∈ X → P ⊆ X
11 1 clsdif ⊢ J ∈ Top ∧ P ⊆ X → cls ⁡ J ⁡ X ∖ P = X ∖ int ⁡ J ⁡ P
12 10 11 sylan2 ⊢ J ∈ Top ∧ P ∈ X → cls ⁡ J ⁡ X ∖ P = X ∖ int ⁡ J ⁡ P
13 12 eleq2d ⊢ J ∈ Top ∧ P ∈ X → P ∈ cls ⁡ J ⁡ X ∖ P ↔ P ∈ X ∖ int ⁡ J ⁡ P
14 eldif ⊢ P ∈ X ∖ int ⁡ J ⁡ P ↔ P ∈ X ∧ ¬ P ∈ int ⁡ J ⁡ P
15 14 baib ⊢ P ∈ X → P ∈ X ∖ int ⁡ J ⁡ P ↔ ¬ P ∈ int ⁡ J ⁡ P
16 15 adantl ⊢ J ∈ Top ∧ P ∈ X → P ∈ X ∖ int ⁡ J ⁡ P ↔ ¬ P ∈ int ⁡ J ⁡ P
17 snssi ⊢ P ∈ int ⁡ J ⁡ P → P ⊆ int ⁡ J ⁡ P
18 17 adantl ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ int ⁡ J ⁡ P → P ⊆ int ⁡ J ⁡ P
19 1 ntrss2 ⊢ J ∈ Top ∧ P ⊆ X → int ⁡ J ⁡ P ⊆ P
20 10 19 sylan2 ⊢ J ∈ Top ∧ P ∈ X → int ⁡ J ⁡ P ⊆ P
21 20 adantr ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ int ⁡ J ⁡ P → int ⁡ J ⁡ P ⊆ P
22 18 21 eqssd ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ int ⁡ J ⁡ P → P = int ⁡ J ⁡ P
23 1 ntropn ⊢ J ∈ Top ∧ P ⊆ X → int ⁡ J ⁡ P ∈ J
24 10 23 sylan2 ⊢ J ∈ Top ∧ P ∈ X → int ⁡ J ⁡ P ∈ J
25 24 adantr ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ int ⁡ J ⁡ P → int ⁡ J ⁡ P ∈ J
26 22 25 eqeltrd ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ int ⁡ J ⁡ P → P ∈ J
27 snidg ⊢ P ∈ X → P ∈ P
28 27 ad2antlr ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ J → P ∈ P
29 isopn3i ⊢ J ∈ Top ∧ P ∈ J → int ⁡ J ⁡ P = P
30 29 adantlr ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ J → int ⁡ J ⁡ P = P
31 28 30 eleqtrrd ⊢ J ∈ Top ∧ P ∈ X ∧ P ∈ J → P ∈ int ⁡ J ⁡ P
32 26 31 impbida ⊢ J ∈ Top ∧ P ∈ X → P ∈ int ⁡ J ⁡ P ↔ P ∈ J
33 32 notbid ⊢ J ∈ Top ∧ P ∈ X → ¬ P ∈ int ⁡ J ⁡ P ↔ ¬ P ∈ J
34 16 33 bitrd ⊢ J ∈ Top ∧ P ∈ X → P ∈ X ∖ int ⁡ J ⁡ P ↔ ¬ P ∈ J
35 9 13 34 3bitrd ⊢ J ∈ Top ∧ P ∈ X → P ∈ limPt ⁡ J ⁡ X ↔ ¬ P ∈ J
36 35 pm5.32da ⊢ J ∈ Top → P ∈ X ∧ P ∈ limPt ⁡ J ⁡ X ↔ P ∈ X ∧ ¬ P ∈ J
37 6 36 bitrd ⊢ J ∈ Top → P ∈ limPt ⁡ J ⁡ X ↔ P ∈ X ∧ ¬ P ∈ J