| Step | Hyp | Ref
 | Expression | 
| 1 |   | df-irdg 6428 | 
. 2
⊢ rec(𝐹, 𝐴) = recs((𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))))) | 
| 2 |   | funmpt 5296 | 
. . 3
⊢ Fun
(𝑔 ∈ V ↦ (𝐴 ∪ ∪ 𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥)))) | 
| 3 | 2 | a1i 9 | 
. 2
⊢ ((𝜑 ∧ 𝐵 ∈ On) → Fun (𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))))) | 
| 4 |   | ordon 4522 | 
. . 3
⊢ Ord
On | 
| 5 | 4 | a1i 9 | 
. 2
⊢ ((𝜑 ∧ 𝐵 ∈ On) → Ord On) | 
| 6 |   | vex 2766 | 
. . . 4
⊢ 𝑓 ∈ V | 
| 7 |   | rdgon.2 | 
. . . . . . 7
⊢ (𝜑 → 𝐴 ∈ On) | 
| 8 | 7 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝐵 ∈ On) → 𝐴 ∈ On) | 
| 9 | 8 | 3ad2ant1 1020 | 
. . . . 5
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → 𝐴 ∈ On) | 
| 10 | 6 | dmex 4932 | 
. . . . . 6
⊢ dom 𝑓 ∈ V | 
| 11 |   | fveq2 5558 | 
. . . . . . . . . 10
⊢ (𝑥 = (𝑓‘𝑧) → (𝐹‘𝑥) = (𝐹‘(𝑓‘𝑧))) | 
| 12 | 11 | eleq1d 2265 | 
. . . . . . . . 9
⊢ (𝑥 = (𝑓‘𝑧) → ((𝐹‘𝑥) ∈ On ↔ (𝐹‘(𝑓‘𝑧)) ∈ On)) | 
| 13 |   | rdgon.3 | 
. . . . . . . . . . . 12
⊢ (𝜑 → ∀𝑥 ∈ On (𝐹‘𝑥) ∈ On) | 
| 14 | 13 | adantr 276 | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ 𝐵 ∈ On) → ∀𝑥 ∈ On (𝐹‘𝑥) ∈ On) | 
| 15 | 14 | 3ad2ant1 1020 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ∀𝑥 ∈ On (𝐹‘𝑥) ∈ On) | 
| 16 | 15 | adantr 276 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → ∀𝑥 ∈ On (𝐹‘𝑥) ∈ On) | 
| 17 |   | simpl3 1004 | 
. . . . . . . . . 10
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → 𝑓:𝑦⟶On) | 
| 18 |   | simpr 110 | 
. . . . . . . . . . 11
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → 𝑧 ∈ dom 𝑓) | 
| 19 |   | fdm 5413 | 
. . . . . . . . . . . . 13
⊢ (𝑓:𝑦⟶On → dom 𝑓 = 𝑦) | 
| 20 | 19 | eleq2d 2266 | 
. . . . . . . . . . . 12
⊢ (𝑓:𝑦⟶On → (𝑧 ∈ dom 𝑓 ↔ 𝑧 ∈ 𝑦)) | 
| 21 | 17, 20 | syl 14 | 
. . . . . . . . . . 11
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → (𝑧 ∈ dom 𝑓 ↔ 𝑧 ∈ 𝑦)) | 
| 22 | 18, 21 | mpbid 147 | 
. . . . . . . . . 10
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → 𝑧 ∈ 𝑦) | 
| 23 | 17, 22 | ffvelcdmd 5698 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → (𝑓‘𝑧) ∈ On) | 
| 24 | 12, 16, 23 | rspcdva 2873 | 
. . . . . . . 8
⊢ ((((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) ∧ 𝑧 ∈ dom 𝑓) → (𝐹‘(𝑓‘𝑧)) ∈ On) | 
| 25 | 24 | ralrimiva 2570 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ∀𝑧 ∈ dom 𝑓(𝐹‘(𝑓‘𝑧)) ∈ On) | 
| 26 |   | fveq2 5558 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑧 → (𝑓‘𝑥) = (𝑓‘𝑧)) | 
| 27 | 26 | fveq2d 5562 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑧 → (𝐹‘(𝑓‘𝑥)) = (𝐹‘(𝑓‘𝑧))) | 
| 28 | 27 | eleq1d 2265 | 
. . . . . . . 8
⊢ (𝑥 = 𝑧 → ((𝐹‘(𝑓‘𝑥)) ∈ On ↔ (𝐹‘(𝑓‘𝑧)) ∈ On)) | 
| 29 | 28 | cbvralv 2729 | 
. . . . . . 7
⊢
(∀𝑥 ∈
dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On ↔ ∀𝑧 ∈ dom 𝑓(𝐹‘(𝑓‘𝑧)) ∈ On) | 
| 30 | 25, 29 | sylibr 134 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ∀𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On) | 
| 31 |   | iunon 6342 | 
. . . . . 6
⊢ ((dom
𝑓 ∈ V ∧
∀𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On) → ∪ 𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On) | 
| 32 | 10, 30, 31 | sylancr 414 | 
. . . . 5
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ∪ 𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On) | 
| 33 |   | onun2 4526 | 
. . . . 5
⊢ ((𝐴 ∈ On ∧ ∪ 𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)) ∈ On) → (𝐴 ∪ ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥))) ∈ On) | 
| 34 | 9, 32, 33 | syl2anc 411 | 
. . . 4
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → (𝐴 ∪ ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥))) ∈ On) | 
| 35 |   | dmeq 4866 | 
. . . . . . 7
⊢ (𝑔 = 𝑓 → dom 𝑔 = dom 𝑓) | 
| 36 |   | fveq1 5557 | 
. . . . . . . 8
⊢ (𝑔 = 𝑓 → (𝑔‘𝑥) = (𝑓‘𝑥)) | 
| 37 | 36 | fveq2d 5562 | 
. . . . . . 7
⊢ (𝑔 = 𝑓 → (𝐹‘(𝑔‘𝑥)) = (𝐹‘(𝑓‘𝑥))) | 
| 38 | 35, 37 | iuneq12d 3940 | 
. . . . . 6
⊢ (𝑔 = 𝑓 → ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥)) = ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥))) | 
| 39 | 38 | uneq2d 3317 | 
. . . . 5
⊢ (𝑔 = 𝑓 → (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))) = (𝐴 ∪ ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)))) | 
| 40 |   | eqid 2196 | 
. . . . 5
⊢ (𝑔 ∈ V ↦ (𝐴 ∪ ∪ 𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥)))) = (𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥)))) | 
| 41 | 39, 40 | fvmptg 5637 | 
. . . 4
⊢ ((𝑓 ∈ V ∧ (𝐴 ∪ ∪ 𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥))) ∈ On) → ((𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))))‘𝑓) = (𝐴 ∪ ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)))) | 
| 42 | 6, 34, 41 | sylancr 414 | 
. . 3
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ((𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))))‘𝑓) = (𝐴 ∪ ∪
𝑥 ∈ dom 𝑓(𝐹‘(𝑓‘𝑥)))) | 
| 43 | 42, 34 | eqeltrd 2273 | 
. 2
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ On ∧ 𝑓:𝑦⟶On) → ((𝑔 ∈ V ↦ (𝐴 ∪ ∪
𝑥 ∈ dom 𝑔(𝐹‘(𝑔‘𝑥))))‘𝑓) ∈ On) | 
| 44 |   | unon 4547 | 
. . . . . 6
⊢ ∪ On = On | 
| 45 | 44 | eleq2i 2263 | 
. . . . 5
⊢ (𝑦 ∈ ∪ On ↔ 𝑦 ∈ On) | 
| 46 | 45 | biimpi 120 | 
. . . 4
⊢ (𝑦 ∈ ∪ On → 𝑦 ∈ On) | 
| 47 | 46 | adantl 277 | 
. . 3
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ ∪ On)
→ 𝑦 ∈
On) | 
| 48 |   | onsuc 4537 | 
. . 3
⊢ (𝑦 ∈ On → suc 𝑦 ∈ On) | 
| 49 | 47, 48 | syl 14 | 
. 2
⊢ (((𝜑 ∧ 𝐵 ∈ On) ∧ 𝑦 ∈ ∪ On)
→ suc 𝑦 ∈
On) | 
| 50 | 44 | eleq2i 2263 | 
. . . 4
⊢ (𝐵 ∈ ∪ On ↔ 𝐵 ∈ On) | 
| 51 | 50 | biimpri 133 | 
. . 3
⊢ (𝐵 ∈ On → 𝐵 ∈ ∪ On) | 
| 52 | 51 | adantl 277 | 
. 2
⊢ ((𝜑 ∧ 𝐵 ∈ On) → 𝐵 ∈ ∪
On) | 
| 53 | 1, 3, 5, 43, 49, 52 | tfrcl 6422 | 
1
⊢ ((𝜑 ∧ 𝐵 ∈ On) → (rec(𝐹, 𝐴)‘𝐵) ∈ On) |