Step |
Hyp |
Ref |
Expression |
1 |
|
vex |
⊢ 𝑥 ∈ V |
2 |
|
inss2 |
⊢ ( 𝑎 ∩ 𝑥 ) ⊆ 𝑥 |
3 |
1 2
|
ssexi |
⊢ ( 𝑎 ∩ 𝑥 ) ∈ V |
4 |
|
idn2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ) |
5 |
|
simpl |
⊢ ( ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) → 𝑥 ∈ 𝑎 ) |
6 |
4 5
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ 𝑥 ∈ 𝑎 ) |
7 |
|
idn1 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) ▶ ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) ) |
8 |
|
simpl |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) → 𝑎 ⊆ On ) |
9 |
7 8
|
e1a |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) ▶ 𝑎 ⊆ On ) |
10 |
|
ssel |
⊢ ( 𝑎 ⊆ On → ( 𝑥 ∈ 𝑎 → 𝑥 ∈ On ) ) |
11 |
10
|
com12 |
⊢ ( 𝑥 ∈ 𝑎 → ( 𝑎 ⊆ On → 𝑥 ∈ On ) ) |
12 |
6 9 11
|
e21 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ 𝑥 ∈ On ) |
13 |
|
eloni |
⊢ ( 𝑥 ∈ On → Ord 𝑥 ) |
14 |
12 13
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ Ord 𝑥 ) |
15 |
|
ordwe |
⊢ ( Ord 𝑥 → E We 𝑥 ) |
16 |
14 15
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ E We 𝑥 ) |
17 |
|
wess |
⊢ ( ( 𝑎 ∩ 𝑥 ) ⊆ 𝑥 → ( E We 𝑥 → E We ( 𝑎 ∩ 𝑥 ) ) ) |
18 |
17
|
com12 |
⊢ ( E We 𝑥 → ( ( 𝑎 ∩ 𝑥 ) ⊆ 𝑥 → E We ( 𝑎 ∩ 𝑥 ) ) ) |
19 |
16 2 18
|
e20 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ E We ( 𝑎 ∩ 𝑥 ) ) |
20 |
|
wefr |
⊢ ( E We ( 𝑎 ∩ 𝑥 ) → E Fr ( 𝑎 ∩ 𝑥 ) ) |
21 |
19 20
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ E Fr ( 𝑎 ∩ 𝑥 ) ) |
22 |
|
dfepfr |
⊢ ( E Fr ( 𝑎 ∩ 𝑥 ) ↔ ∀ 𝑏 ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ) |
23 |
22
|
biimpi |
⊢ ( E Fr ( 𝑎 ∩ 𝑥 ) → ∀ 𝑏 ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ) |
24 |
21 23
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ∀ 𝑏 ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ) |
25 |
|
spsbc |
⊢ ( ( 𝑎 ∩ 𝑥 ) ∈ V → ( ∀ 𝑏 ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) → [ ( 𝑎 ∩ 𝑥 ) / 𝑏 ] ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ) ) |
26 |
3 24 25
|
e02 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ [ ( 𝑎 ∩ 𝑥 ) / 𝑏 ] ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ) |
27 |
|
onfrALTlem5 |
⊢ ( [ ( 𝑎 ∩ 𝑥 ) / 𝑏 ] ( ( 𝑏 ⊆ ( 𝑎 ∩ 𝑥 ) ∧ 𝑏 ≠ ∅ ) → ∃ 𝑦 ∈ 𝑏 ( 𝑏 ∩ 𝑦 ) = ∅ ) ↔ ( ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) → ∃ 𝑦 ∈ ( 𝑎 ∩ 𝑥 ) ( ( 𝑎 ∩ 𝑥 ) ∩ 𝑦 ) = ∅ ) ) |
28 |
26 27
|
e2bi |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ( ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) → ∃ 𝑦 ∈ ( 𝑎 ∩ 𝑥 ) ( ( 𝑎 ∩ 𝑥 ) ∩ 𝑦 ) = ∅ ) ) |
29 |
|
ssid |
⊢ ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) |
30 |
|
simpr |
⊢ ( ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) → ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) |
31 |
4 30
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) |
32 |
|
df-ne |
⊢ ( ( 𝑎 ∩ 𝑥 ) ≠ ∅ ↔ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) |
33 |
32
|
biimpri |
⊢ ( ¬ ( 𝑎 ∩ 𝑥 ) = ∅ → ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) |
34 |
31 33
|
e2 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) |
35 |
|
pm3.2 |
⊢ ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) → ( ( 𝑎 ∩ 𝑥 ) ≠ ∅ → ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) ) ) |
36 |
29 34 35
|
e02 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) ) |
37 |
|
id |
⊢ ( ( ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) → ∃ 𝑦 ∈ ( 𝑎 ∩ 𝑥 ) ( ( 𝑎 ∩ 𝑥 ) ∩ 𝑦 ) = ∅ ) → ( ( ( 𝑎 ∩ 𝑥 ) ⊆ ( 𝑎 ∩ 𝑥 ) ∧ ( 𝑎 ∩ 𝑥 ) ≠ ∅ ) → ∃ 𝑦 ∈ ( 𝑎 ∩ 𝑥 ) ( ( 𝑎 ∩ 𝑥 ) ∩ 𝑦 ) = ∅ ) ) |
38 |
28 36 37
|
e22 |
⊢ ( ( 𝑎 ⊆ On ∧ 𝑎 ≠ ∅ ) , ( 𝑥 ∈ 𝑎 ∧ ¬ ( 𝑎 ∩ 𝑥 ) = ∅ ) ▶ ∃ 𝑦 ∈ ( 𝑎 ∩ 𝑥 ) ( ( 𝑎 ∩ 𝑥 ) ∩ 𝑦 ) = ∅ ) |