Step |
Hyp |
Ref |
Expression |
1 |
|
simpr |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → 𝐽 ≈ 2o ) |
2 |
|
toponss |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝑥 ∈ 𝐽 ) → 𝑥 ⊆ 𝑋 ) |
3 |
2
|
ad2ant2rl |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ ( 𝑋 = ∅ ∧ 𝑥 ∈ 𝐽 ) ) → 𝑥 ⊆ 𝑋 ) |
4 |
|
simprl |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ ( 𝑋 = ∅ ∧ 𝑥 ∈ 𝐽 ) ) → 𝑋 = ∅ ) |
5 |
|
sseq0 |
⊢ ( ( 𝑥 ⊆ 𝑋 ∧ 𝑋 = ∅ ) → 𝑥 = ∅ ) |
6 |
3 4 5
|
syl2anc |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ ( 𝑋 = ∅ ∧ 𝑥 ∈ 𝐽 ) ) → 𝑥 = ∅ ) |
7 |
|
velsn |
⊢ ( 𝑥 ∈ { ∅ } ↔ 𝑥 = ∅ ) |
8 |
6 7
|
sylibr |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ ( 𝑋 = ∅ ∧ 𝑥 ∈ 𝐽 ) ) → 𝑥 ∈ { ∅ } ) |
9 |
8
|
expr |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → ( 𝑥 ∈ 𝐽 → 𝑥 ∈ { ∅ } ) ) |
10 |
9
|
ssrdv |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → 𝐽 ⊆ { ∅ } ) |
11 |
|
topontop |
⊢ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) → 𝐽 ∈ Top ) |
12 |
|
0opn |
⊢ ( 𝐽 ∈ Top → ∅ ∈ 𝐽 ) |
13 |
11 12
|
syl |
⊢ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) → ∅ ∈ 𝐽 ) |
14 |
13
|
ad2antrr |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → ∅ ∈ 𝐽 ) |
15 |
14
|
snssd |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → { ∅ } ⊆ 𝐽 ) |
16 |
10 15
|
eqssd |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → 𝐽 = { ∅ } ) |
17 |
|
0ex |
⊢ ∅ ∈ V |
18 |
17
|
ensn1 |
⊢ { ∅ } ≈ 1o |
19 |
16 18
|
eqbrtrdi |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → 𝐽 ≈ 1o ) |
20 |
19
|
olcd |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → ( 𝐽 = ∅ ∨ 𝐽 ≈ 1o ) ) |
21 |
|
sdom2en01 |
⊢ ( 𝐽 ≺ 2o ↔ ( 𝐽 = ∅ ∨ 𝐽 ≈ 1o ) ) |
22 |
20 21
|
sylibr |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → 𝐽 ≺ 2o ) |
23 |
|
sdomnen |
⊢ ( 𝐽 ≺ 2o → ¬ 𝐽 ≈ 2o ) |
24 |
22 23
|
syl |
⊢ ( ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) ∧ 𝑋 = ∅ ) → ¬ 𝐽 ≈ 2o ) |
25 |
24
|
ex |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ( 𝑋 = ∅ → ¬ 𝐽 ≈ 2o ) ) |
26 |
25
|
necon2ad |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ( 𝐽 ≈ 2o → 𝑋 ≠ ∅ ) ) |
27 |
1 26
|
mpd |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → 𝑋 ≠ ∅ ) |
28 |
27
|
necomd |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ∅ ≠ 𝑋 ) |
29 |
13
|
adantr |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ∅ ∈ 𝐽 ) |
30 |
|
toponmax |
⊢ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) → 𝑋 ∈ 𝐽 ) |
31 |
30
|
adantr |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → 𝑋 ∈ 𝐽 ) |
32 |
|
en2eqpr |
⊢ ( ( 𝐽 ≈ 2o ∧ ∅ ∈ 𝐽 ∧ 𝑋 ∈ 𝐽 ) → ( ∅ ≠ 𝑋 → 𝐽 = { ∅ , 𝑋 } ) ) |
33 |
1 29 31 32
|
syl3anc |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ( ∅ ≠ 𝑋 → 𝐽 = { ∅ , 𝑋 } ) ) |
34 |
28 33
|
mpd |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → 𝐽 = { ∅ , 𝑋 } ) |
35 |
34 27
|
jca |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ 𝐽 ≈ 2o ) → ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) |
36 |
|
simprl |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) → 𝐽 = { ∅ , 𝑋 } ) |
37 |
|
simprr |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) → 𝑋 ≠ ∅ ) |
38 |
37
|
necomd |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) → ∅ ≠ 𝑋 ) |
39 |
|
pr2nelem |
⊢ ( ( ∅ ∈ V ∧ 𝑋 ∈ 𝐽 ∧ ∅ ≠ 𝑋 ) → { ∅ , 𝑋 } ≈ 2o ) |
40 |
17 30 38 39
|
mp3an2ani |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) → { ∅ , 𝑋 } ≈ 2o ) |
41 |
36 40
|
eqbrtrd |
⊢ ( ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) ∧ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) → 𝐽 ≈ 2o ) |
42 |
35 41
|
impbida |
⊢ ( 𝐽 ∈ ( TopOn ‘ 𝑋 ) → ( 𝐽 ≈ 2o ↔ ( 𝐽 = { ∅ , 𝑋 } ∧ 𝑋 ≠ ∅ ) ) ) |