Proof of Theorem dfrdg3
| Step | Hyp | Ref
| Expression |
| 1 | | dfrdg2 35796 |
. . 3
⊢ (𝐼 ∈ V → rec(𝐹, 𝐼) = ∪ {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 2 | | iftrue 4531 |
. . . . . . . . . 10
⊢ (𝐼 ∈ V → if(𝐼 ∈ V, 𝐼, ∅) = 𝐼) |
| 3 | 2 | ifeq1d 4545 |
. . . . . . . . 9
⊢ (𝐼 ∈ V → if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) |
| 4 | 3 | eqeq2d 2748 |
. . . . . . . 8
⊢ (𝐼 ∈ V → ((𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) ↔ (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))) |
| 5 | 4 | ralbidv 3178 |
. . . . . . 7
⊢ (𝐼 ∈ V → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) ↔ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))) |
| 6 | 5 | anbi2d 630 |
. . . . . 6
⊢ (𝐼 ∈ V → ((𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) ↔ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))))) |
| 7 | 6 | rexbidv 3179 |
. . . . 5
⊢ (𝐼 ∈ V → (∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) ↔ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))))) |
| 8 | 7 | abbidv 2808 |
. . . 4
⊢ (𝐼 ∈ V → {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} = {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 9 | 8 | unieqd 4920 |
. . 3
⊢ (𝐼 ∈ V → ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} = ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, 𝐼, if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 10 | 1, 9 | eqtr4d 2780 |
. 2
⊢ (𝐼 ∈ V → rec(𝐹, 𝐼) = ∪ {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 11 | | 0ex 5307 |
. . . 4
⊢ ∅
∈ V |
| 12 | | dfrdg2 35796 |
. . . 4
⊢ (∅
∈ V → rec(𝐹,
∅) = ∪ {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 13 | 11, 12 | ax-mp 5 |
. . 3
⊢ rec(𝐹, ∅) = ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} |
| 14 | | rdgprc 35795 |
. . 3
⊢ (¬
𝐼 ∈ V → rec(𝐹, 𝐼) = rec(𝐹, ∅)) |
| 15 | | iffalse 4534 |
. . . . . . . . . 10
⊢ (¬
𝐼 ∈ V → if(𝐼 ∈ V, 𝐼, ∅) = ∅) |
| 16 | 15 | ifeq1d 4545 |
. . . . . . . . 9
⊢ (¬
𝐼 ∈ V → if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) |
| 17 | 16 | eqeq2d 2748 |
. . . . . . . 8
⊢ (¬
𝐼 ∈ V → ((𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) ↔ (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))) |
| 18 | 17 | ralbidv 3178 |
. . . . . . 7
⊢ (¬
𝐼 ∈ V →
(∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))) ↔ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))) |
| 19 | 18 | anbi2d 630 |
. . . . . 6
⊢ (¬
𝐼 ∈ V → ((𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) ↔ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))))) |
| 20 | 19 | rexbidv 3179 |
. . . . 5
⊢ (¬
𝐼 ∈ V →
(∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))) ↔ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦))))))) |
| 21 | 20 | abbidv 2808 |
. . . 4
⊢ (¬
𝐼 ∈ V → {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} = {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 22 | 21 | unieqd 4920 |
. . 3
⊢ (¬
𝐼 ∈ V → ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} = ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, ∅, if(Lim 𝑦, ∪
(𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 23 | 13, 14, 22 | 3eqtr4a 2803 |
. 2
⊢ (¬
𝐼 ∈ V → rec(𝐹, 𝐼) = ∪ {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))}) |
| 24 | 10, 23 | pm2.61i 182 |
1
⊢ rec(𝐹, 𝐼) = ∪ {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = if(𝑦 = ∅, if(𝐼 ∈ V, 𝐼, ∅), if(Lim 𝑦, ∪ (𝑓 “ 𝑦), (𝐹‘(𝑓‘∪ 𝑦)))))} |