| Step | Hyp | Ref
| Expression |
| 1 | | vex 3468 |
. . . . 5
⊢ 𝑥 ∈ V |
| 2 | | inss2 4218 |
. . . . 5
⊢ (𝑎 ∩ 𝑥) ⊆ 𝑥 |
| 3 | 1, 2 | ssexi 5297 |
. . . 4
⊢ (𝑎 ∩ 𝑥) ∈ V |
| 4 | | idn2 44605 |
. . . . . . . . . . 11
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ) |
| 5 | | simpl 482 |
. . . . . . . . . . 11
⊢ ((𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) → 𝑥 ∈ 𝑎) |
| 6 | 4, 5 | e2 44623 |
. . . . . . . . . 10
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ 𝑥 ∈ 𝑎 ) |
| 7 | | idn1 44566 |
. . . . . . . . . . 11
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) ▶ (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) ) |
| 8 | | simpl 482 |
. . . . . . . . . . 11
⊢ ((𝑎 ⊆ On ∧ 𝑎 ≠ ∅) → 𝑎 ⊆ On) |
| 9 | 7, 8 | e1a 44619 |
. . . . . . . . . 10
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) ▶ 𝑎 ⊆ On ) |
| 10 | | ssel 3957 |
. . . . . . . . . . 11
⊢ (𝑎 ⊆ On → (𝑥 ∈ 𝑎 → 𝑥 ∈ On)) |
| 11 | 10 | com12 32 |
. . . . . . . . . 10
⊢ (𝑥 ∈ 𝑎 → (𝑎 ⊆ On → 𝑥 ∈ On)) |
| 12 | 6, 9, 11 | e21 44721 |
. . . . . . . . 9
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ 𝑥 ∈ On ) |
| 13 | | eloni 6367 |
. . . . . . . . 9
⊢ (𝑥 ∈ On → Ord 𝑥) |
| 14 | 12, 13 | e2 44623 |
. . . . . . . 8
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ Ord 𝑥 ) |
| 15 | | ordwe 6370 |
. . . . . . . 8
⊢ (Ord
𝑥 → E We 𝑥) |
| 16 | 14, 15 | e2 44623 |
. . . . . . 7
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ E We
𝑥 ) |
| 17 | | wess 5645 |
. . . . . . . 8
⊢ ((𝑎 ∩ 𝑥) ⊆ 𝑥 → ( E We 𝑥 → E We (𝑎 ∩ 𝑥))) |
| 18 | 17 | com12 32 |
. . . . . . 7
⊢ ( E We
𝑥 → ((𝑎 ∩ 𝑥) ⊆ 𝑥 → E We (𝑎 ∩ 𝑥))) |
| 19 | 16, 2, 18 | e20 44718 |
. . . . . 6
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ E We
(𝑎 ∩ 𝑥) ) |
| 20 | | wefr 5649 |
. . . . . 6
⊢ ( E We
(𝑎 ∩ 𝑥) → E Fr (𝑎 ∩ 𝑥)) |
| 21 | 19, 20 | e2 44623 |
. . . . 5
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ E Fr
(𝑎 ∩ 𝑥) ) |
| 22 | | dfepfr 5643 |
. . . . . 6
⊢ ( E Fr
(𝑎 ∩ 𝑥) ↔ ∀𝑏((𝑏 ⊆ (𝑎 ∩ 𝑥) ∧ 𝑏 ≠ ∅) → ∃𝑦 ∈ 𝑏 (𝑏 ∩ 𝑦) = ∅)) |
| 23 | 22 | biimpi 216 |
. . . . 5
⊢ ( E Fr
(𝑎 ∩ 𝑥) → ∀𝑏((𝑏 ⊆ (𝑎 ∩ 𝑥) ∧ 𝑏 ≠ ∅) → ∃𝑦 ∈ 𝑏 (𝑏 ∩ 𝑦) = ∅)) |
| 24 | 21, 23 | e2 44623 |
. . . 4
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ ∀𝑏((𝑏 ⊆ (𝑎 ∩ 𝑥) ∧ 𝑏 ≠ ∅) → ∃𝑦 ∈ 𝑏 (𝑏 ∩ 𝑦) = ∅) ) |
| 25 | | spsbc 3783 |
. . . 4
⊢ ((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 44689 |
. . 3
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ [(𝑎 ∩ 𝑥) / 𝑏]((𝑏 ⊆ (𝑎 ∩ 𝑥) ∧ 𝑏 ≠ ∅) → ∃𝑦 ∈ 𝑏 (𝑏 ∩ 𝑦) = ∅) ) |
| 27 | | onfrALTlem5 44534 |
. . 3
⊢
([(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 44624 |
. 2
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ (((𝑎 ∩ 𝑥) ⊆ (𝑎 ∩ 𝑥) ∧ (𝑎 ∩ 𝑥) ≠ ∅) → ∃𝑦 ∈ (𝑎 ∩ 𝑥)((𝑎 ∩ 𝑥) ∩ 𝑦) = ∅) ) |
| 29 | | ssid 3986 |
. . 3
⊢ (𝑎 ∩ 𝑥) ⊆ (𝑎 ∩ 𝑥) |
| 30 | | simpr 484 |
. . . . 5
⊢ ((𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) → ¬ (𝑎 ∩ 𝑥) = ∅) |
| 31 | 4, 30 | e2 44623 |
. . . 4
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ ¬
(𝑎 ∩ 𝑥) = ∅ ) |
| 32 | | df-ne 2934 |
. . . . 5
⊢ ((𝑎 ∩ 𝑥) ≠ ∅ ↔ ¬ (𝑎 ∩ 𝑥) = ∅) |
| 33 | 32 | biimpri 228 |
. . . 4
⊢ (¬
(𝑎 ∩ 𝑥) = ∅ → (𝑎 ∩ 𝑥) ≠ ∅) |
| 34 | 31, 33 | e2 44623 |
. . 3
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ (𝑎 ∩ 𝑥) ≠ ∅ ) |
| 35 | | pm3.2 469 |
. . 3
⊢ ((𝑎 ∩ 𝑥) ⊆ (𝑎 ∩ 𝑥) → ((𝑎 ∩ 𝑥) ≠ ∅ → ((𝑎 ∩ 𝑥) ⊆ (𝑎 ∩ 𝑥) ∧ (𝑎 ∩ 𝑥) ≠ ∅))) |
| 36 | 29, 34, 35 | e02 44689 |
. 2
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ ((𝑎 ∩ 𝑥) ⊆ (𝑎 ∩ 𝑥) ∧ (𝑎 ∩ 𝑥) ≠ ∅) ) |
| 37 | | id 22 |
. 2
⊢ ((((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 44663 |
1
⊢ ( (𝑎 ⊆ On ∧ 𝑎 ≠ ∅) , (𝑥 ∈ 𝑎 ∧ ¬ (𝑎 ∩ 𝑥) = ∅) ▶ ∃𝑦 ∈ (𝑎 ∩ 𝑥)((𝑎 ∩ 𝑥) ∩ 𝑦) = ∅ ) |