| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | eldm2g 5910 | . . 3
⊢ (𝐵 ∈ dom recs(𝐹) → (𝐵 ∈ dom recs(𝐹) ↔ ∃𝑧〈𝐵, 𝑧〉 ∈ recs(𝐹))) | 
| 2 | 1 | ibi 267 | . 2
⊢ (𝐵 ∈ dom recs(𝐹) → ∃𝑧〈𝐵, 𝑧〉 ∈ recs(𝐹)) | 
| 3 |  | dfrecs3 8412 | . . . . . 6
⊢
recs(𝐹) = ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))} | 
| 4 | 3 | eleq2i 2833 | . . . . 5
⊢
(〈𝐵, 𝑧〉 ∈ recs(𝐹) ↔ 〈𝐵, 𝑧〉 ∈ ∪
{𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))}) | 
| 5 |  | eluniab 4921 | . . . . 5
⊢
(〈𝐵, 𝑧〉 ∈ ∪ {𝑓
∣ ∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))} ↔ ∃𝑓(〈𝐵, 𝑧〉 ∈ 𝑓 ∧ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦))))) | 
| 6 | 4, 5 | bitri 275 | . . . 4
⊢
(〈𝐵, 𝑧〉 ∈ recs(𝐹) ↔ ∃𝑓(〈𝐵, 𝑧〉 ∈ 𝑓 ∧ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦))))) | 
| 7 |  | fnop 6677 | . . . . . . . . . . . . . 14
⊢ ((𝑓 Fn 𝑥 ∧ 〈𝐵, 𝑧〉 ∈ 𝑓) → 𝐵 ∈ 𝑥) | 
| 8 |  | rspe 3249 | . . . . . . . . . . . . . . . 16
⊢ ((𝑥 ∈ On ∧ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) | 
| 9 |  | tfrlem.1 | . . . . . . . . . . . . . . . . . 18
⊢ 𝐴 = {𝑓 ∣ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))} | 
| 10 | 9 | eqabri 2885 | . . . . . . . . . . . . . . . . 17
⊢ (𝑓 ∈ 𝐴 ↔ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) | 
| 11 |  | elssuni 4937 | . . . . . . . . . . . . . . . . . 18
⊢ (𝑓 ∈ 𝐴 → 𝑓 ⊆ ∪ 𝐴) | 
| 12 | 9 | recsfval 8421 | . . . . . . . . . . . . . . . . . 18
⊢
recs(𝐹) = ∪ 𝐴 | 
| 13 | 11, 12 | sseqtrrdi 4025 | . . . . . . . . . . . . . . . . 17
⊢ (𝑓 ∈ 𝐴 → 𝑓 ⊆ recs(𝐹)) | 
| 14 | 10, 13 | sylbir 235 | . . . . . . . . . . . . . . . 16
⊢
(∃𝑥 ∈ On
(𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦))) → 𝑓 ⊆ recs(𝐹)) | 
| 15 | 8, 14 | syl 17 | . . . . . . . . . . . . . . 15
⊢ ((𝑥 ∈ On ∧ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → 𝑓 ⊆ recs(𝐹)) | 
| 16 |  | fveq2 6906 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑦 = 𝐵 → (𝑓‘𝑦) = (𝑓‘𝐵)) | 
| 17 |  | reseq2 5992 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑦 = 𝐵 → (𝑓 ↾ 𝑦) = (𝑓 ↾ 𝐵)) | 
| 18 | 17 | fveq2d 6910 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑦 = 𝐵 → (𝐹‘(𝑓 ↾ 𝑦)) = (𝐹‘(𝑓 ↾ 𝐵))) | 
| 19 | 16, 18 | eqeq12d 2753 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 = 𝐵 → ((𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) ↔ (𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)))) | 
| 20 | 19 | rspcv 3618 | . . . . . . . . . . . . . . . . . 18
⊢ (𝐵 ∈ 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)))) | 
| 21 |  | fndm 6671 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑓 Fn 𝑥 → dom 𝑓 = 𝑥) | 
| 22 | 21 | eleq2d 2827 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑓 Fn 𝑥 → (𝐵 ∈ dom 𝑓 ↔ 𝐵 ∈ 𝑥)) | 
| 23 | 9 | tfrlem7 8423 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ Fun
recs(𝐹) | 
| 24 |  | funssfv 6927 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((Fun
recs(𝐹) ∧ 𝑓 ⊆ recs(𝐹) ∧ 𝐵 ∈ dom 𝑓) → (recs(𝐹)‘𝐵) = (𝑓‘𝐵)) | 
| 25 | 23, 24 | mp3an1 1450 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑓 ⊆ recs(𝐹) ∧ 𝐵 ∈ dom 𝑓) → (recs(𝐹)‘𝐵) = (𝑓‘𝐵)) | 
| 26 | 25 | adantrl 716 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑓 ⊆ recs(𝐹) ∧ ((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓)) → (recs(𝐹)‘𝐵) = (𝑓‘𝐵)) | 
| 27 | 21 | eleq1d 2826 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (𝑓 Fn 𝑥 → (dom 𝑓 ∈ On ↔ 𝑥 ∈ On)) | 
| 28 |  | onelss 6426 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ (dom
𝑓 ∈ On → (𝐵 ∈ dom 𝑓 → 𝐵 ⊆ dom 𝑓)) | 
| 29 | 27, 28 | biimtrrdi 254 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ (𝑓 Fn 𝑥 → (𝑥 ∈ On → (𝐵 ∈ dom 𝑓 → 𝐵 ⊆ dom 𝑓))) | 
| 30 | 29 | imp31 417 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ (((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓) → 𝐵 ⊆ dom 𝑓) | 
| 31 |  | fun2ssres 6611 | . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
⊢ ((Fun
recs(𝐹) ∧ 𝑓 ⊆ recs(𝐹) ∧ 𝐵 ⊆ dom 𝑓) → (recs(𝐹) ↾ 𝐵) = (𝑓 ↾ 𝐵)) | 
| 32 | 31 | fveq2d 6910 | . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
⊢ ((Fun
recs(𝐹) ∧ 𝑓 ⊆ recs(𝐹) ∧ 𝐵 ⊆ dom 𝑓) → (𝐹‘(recs(𝐹) ↾ 𝐵)) = (𝐹‘(𝑓 ↾ 𝐵))) | 
| 33 | 23, 32 | mp3an1 1450 | . . . . . . . . . . . . . . . . . . . . . . . . . . 27
⊢ ((𝑓 ⊆ recs(𝐹) ∧ 𝐵 ⊆ dom 𝑓) → (𝐹‘(recs(𝐹) ↾ 𝐵)) = (𝐹‘(𝑓 ↾ 𝐵))) | 
| 34 | 30, 33 | sylan2 593 | . . . . . . . . . . . . . . . . . . . . . . . . . 26
⊢ ((𝑓 ⊆ recs(𝐹) ∧ ((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓)) → (𝐹‘(recs(𝐹) ↾ 𝐵)) = (𝐹‘(𝑓 ↾ 𝐵))) | 
| 35 | 26, 34 | eqeq12d 2753 | . . . . . . . . . . . . . . . . . . . . . . . . 25
⊢ ((𝑓 ⊆ recs(𝐹) ∧ ((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓)) → ((recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)) ↔ (𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)))) | 
| 36 | 35 | exbiri 811 | . . . . . . . . . . . . . . . . . . . . . . . 24
⊢ (𝑓 ⊆ recs(𝐹) → (((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓) → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))) | 
| 37 | 36 | com3l 89 | . . . . . . . . . . . . . . . . . . . . . . 23
⊢ (((𝑓 Fn 𝑥 ∧ 𝑥 ∈ On) ∧ 𝐵 ∈ dom 𝑓) → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))) | 
| 38 | 37 | exp31 419 | . . . . . . . . . . . . . . . . . . . . . 22
⊢ (𝑓 Fn 𝑥 → (𝑥 ∈ On → (𝐵 ∈ dom 𝑓 → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 39 | 38 | com34 91 | . . . . . . . . . . . . . . . . . . . . 21
⊢ (𝑓 Fn 𝑥 → (𝑥 ∈ On → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝐵 ∈ dom 𝑓 → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 40 | 39 | com24 95 | . . . . . . . . . . . . . . . . . . . 20
⊢ (𝑓 Fn 𝑥 → (𝐵 ∈ dom 𝑓 → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝑥 ∈ On → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 41 | 22, 40 | sylbird 260 | . . . . . . . . . . . . . . . . . . 19
⊢ (𝑓 Fn 𝑥 → (𝐵 ∈ 𝑥 → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝑥 ∈ On → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 42 | 41 | com3l 89 | . . . . . . . . . . . . . . . . . 18
⊢ (𝐵 ∈ 𝑥 → ((𝑓‘𝐵) = (𝐹‘(𝑓 ↾ 𝐵)) → (𝑓 Fn 𝑥 → (𝑥 ∈ On → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 43 | 20, 42 | syld 47 | . . . . . . . . . . . . . . . . 17
⊢ (𝐵 ∈ 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (𝑓 Fn 𝑥 → (𝑥 ∈ On → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 44 | 43 | com24 95 | . . . . . . . . . . . . . . . 16
⊢ (𝐵 ∈ 𝑥 → (𝑥 ∈ On → (𝑓 Fn 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 45 | 44 | imp4d 424 | . . . . . . . . . . . . . . 15
⊢ (𝐵 ∈ 𝑥 → ((𝑥 ∈ On ∧ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → (𝑓 ⊆ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))) | 
| 46 | 15, 45 | mpdi 45 | . . . . . . . . . . . . . 14
⊢ (𝐵 ∈ 𝑥 → ((𝑥 ∈ On ∧ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))) | 
| 47 | 7, 46 | syl 17 | . . . . . . . . . . . . 13
⊢ ((𝑓 Fn 𝑥 ∧ 〈𝐵, 𝑧〉 ∈ 𝑓) → ((𝑥 ∈ On ∧ (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))) | 
| 48 | 47 | exp4d 433 | . . . . . . . . . . . 12
⊢ ((𝑓 Fn 𝑥 ∧ 〈𝐵, 𝑧〉 ∈ 𝑓) → (𝑥 ∈ On → (𝑓 Fn 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))))) | 
| 49 | 48 | ex 412 | . . . . . . . . . . 11
⊢ (𝑓 Fn 𝑥 → (〈𝐵, 𝑧〉 ∈ 𝑓 → (𝑥 ∈ On → (𝑓 Fn 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 50 | 49 | com4r 94 | . . . . . . . . . 10
⊢ (𝑓 Fn 𝑥 → (𝑓 Fn 𝑥 → (〈𝐵, 𝑧〉 ∈ 𝑓 → (𝑥 ∈ On → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))))) | 
| 51 | 50 | pm2.43i 52 | . . . . . . . . 9
⊢ (𝑓 Fn 𝑥 → (〈𝐵, 𝑧〉 ∈ 𝑓 → (𝑥 ∈ On → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))))) | 
| 52 | 51 | com3l 89 | . . . . . . . 8
⊢
(〈𝐵, 𝑧〉 ∈ 𝑓 → (𝑥 ∈ On → (𝑓 Fn 𝑥 → (∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))))) | 
| 53 | 52 | imp4a 422 | . . . . . . 7
⊢
(〈𝐵, 𝑧〉 ∈ 𝑓 → (𝑥 ∈ On → ((𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))))) | 
| 54 | 53 | rexlimdv 3153 | . . . . . 6
⊢
(〈𝐵, 𝑧〉 ∈ 𝑓 → (∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵)))) | 
| 55 | 54 | imp 406 | . . . . 5
⊢
((〈𝐵, 𝑧〉 ∈ 𝑓 ∧ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))) | 
| 56 | 55 | exlimiv 1930 | . . . 4
⊢
(∃𝑓(〈𝐵, 𝑧〉 ∈ 𝑓 ∧ ∃𝑥 ∈ On (𝑓 Fn 𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) = (𝐹‘(𝑓 ↾ 𝑦)))) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))) | 
| 57 | 6, 56 | sylbi 217 | . . 3
⊢
(〈𝐵, 𝑧〉 ∈ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))) | 
| 58 | 57 | exlimiv 1930 | . 2
⊢
(∃𝑧〈𝐵, 𝑧〉 ∈ recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))) | 
| 59 | 2, 58 | syl 17 | 1
⊢ (𝐵 ∈ dom recs(𝐹) → (recs(𝐹)‘𝐵) = (𝐹‘(recs(𝐹) ↾ 𝐵))) |