| Step | Hyp | Ref
| Expression |
| 1 | | dfatafv2iota 47222 |
. 2
⊢ (𝐹 defAt 𝐴 → (𝐹''''𝐴) = (℩𝑦𝐴𝐹𝑦)) |
| 2 | | df-dfat 47131 |
. . 3
⊢ (𝐹 defAt 𝐴 ↔ (𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴}))) |
| 3 | | sneq 4636 |
. . . . . . . . 9
⊢ (𝑥 = 𝐴 → {𝑥} = {𝐴}) |
| 4 | 3 | reseq2d 5997 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → (𝐹 ↾ {𝑥}) = (𝐹 ↾ {𝐴})) |
| 5 | 4 | funeqd 6588 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (Fun (𝐹 ↾ {𝑥}) ↔ Fun (𝐹 ↾ {𝐴}))) |
| 6 | | eleq1 2829 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (𝑥 ∈ dom 𝐹 ↔ 𝐴 ∈ dom 𝐹)) |
| 7 | 5, 6 | anbi12d 632 |
. . . . . 6
⊢ (𝑥 = 𝐴 → ((Fun (𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) ↔ (Fun (𝐹 ↾ {𝐴}) ∧ 𝐴 ∈ dom 𝐹))) |
| 8 | | breq1 5146 |
. . . . . . . 8
⊢ (𝑥 = 𝐴 → (𝑥𝐹𝑦 ↔ 𝐴𝐹𝑦)) |
| 9 | 8 | iotabidv 6545 |
. . . . . . 7
⊢ (𝑥 = 𝐴 → (℩𝑦𝑥𝐹𝑦) = (℩𝑦𝐴𝐹𝑦)) |
| 10 | 9 | eleq1d 2826 |
. . . . . 6
⊢ (𝑥 = 𝐴 → ((℩𝑦𝑥𝐹𝑦) ∈ ran 𝐹 ↔ (℩𝑦𝐴𝐹𝑦) ∈ ran 𝐹)) |
| 11 | 7, 10 | imbi12d 344 |
. . . . 5
⊢ (𝑥 = 𝐴 → (((Fun (𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → (℩𝑦𝑥𝐹𝑦) ∈ ran 𝐹) ↔ ((Fun (𝐹 ↾ {𝐴}) ∧ 𝐴 ∈ dom 𝐹) → (℩𝑦𝐴𝐹𝑦) ∈ ran 𝐹))) |
| 12 | | eqid 2737 |
. . . . . . . . 9
⊢
(℩𝑦𝑥𝐹𝑦) = (℩𝑦𝑥𝐹𝑦) |
| 13 | | iotaex 6534 |
. . . . . . . . . 10
⊢
(℩𝑦𝑥𝐹𝑦) ∈ V |
| 14 | | eqeq2 2749 |
. . . . . . . . . . . 12
⊢ (𝑧 = (℩𝑦𝑥𝐹𝑦) → ((℩𝑦𝑥𝐹𝑦) = 𝑧 ↔ (℩𝑦𝑥𝐹𝑦) = (℩𝑦𝑥𝐹𝑦))) |
| 15 | | breq2 5147 |
. . . . . . . . . . . 12
⊢ (𝑧 = (℩𝑦𝑥𝐹𝑦) → (𝑥𝐹𝑧 ↔ 𝑥𝐹(℩𝑦𝑥𝐹𝑦))) |
| 16 | 14, 15 | bibi12d 345 |
. . . . . . . . . . 11
⊢ (𝑧 = (℩𝑦𝑥𝐹𝑦) → (((℩𝑦𝑥𝐹𝑦) = 𝑧 ↔ 𝑥𝐹𝑧) ↔ ((℩𝑦𝑥𝐹𝑦) = (℩𝑦𝑥𝐹𝑦) ↔ 𝑥𝐹(℩𝑦𝑥𝐹𝑦)))) |
| 17 | 16 | imbi2d 340 |
. . . . . . . . . 10
⊢ (𝑧 = (℩𝑦𝑥𝐹𝑦) → (((Fun (𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ((℩𝑦𝑥𝐹𝑦) = 𝑧 ↔ 𝑥𝐹𝑧)) ↔ ((Fun (𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ((℩𝑦𝑥𝐹𝑦) = (℩𝑦𝑥𝐹𝑦) ↔ 𝑥𝐹(℩𝑦𝑥𝐹𝑦))))) |
| 18 | | eldmg 5909 |
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ dom 𝐹 → (𝑥 ∈ dom 𝐹 ↔ ∃𝑧 𝑥𝐹𝑧)) |
| 19 | 18 | ibi 267 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ dom 𝐹 → ∃𝑧 𝑥𝐹𝑧) |
| 20 | 19 | adantl 481 |
. . . . . . . . . . . 12
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ∃𝑧 𝑥𝐹𝑧) |
| 21 | | funressnvmo 47057 |
. . . . . . . . . . . . . 14
⊢ (Fun
(𝐹 ↾ {𝑥}) → ∃*𝑧 𝑥𝐹𝑧) |
| 22 | 21 | adantr 480 |
. . . . . . . . . . . . 13
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ∃*𝑧 𝑥𝐹𝑧) |
| 23 | | moeu 2583 |
. . . . . . . . . . . . 13
⊢
(∃*𝑧 𝑥𝐹𝑧 ↔ (∃𝑧 𝑥𝐹𝑧 → ∃!𝑧 𝑥𝐹𝑧)) |
| 24 | 22, 23 | sylib 218 |
. . . . . . . . . . . 12
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → (∃𝑧 𝑥𝐹𝑧 → ∃!𝑧 𝑥𝐹𝑧)) |
| 25 | 20, 24 | mpd 15 |
. . . . . . . . . . 11
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ∃!𝑧 𝑥𝐹𝑧) |
| 26 | | iota1 6538 |
. . . . . . . . . . . 12
⊢
(∃!𝑧 𝑥𝐹𝑧 → (𝑥𝐹𝑧 ↔ (℩𝑧𝑥𝐹𝑧) = 𝑧)) |
| 27 | | breq2 5147 |
. . . . . . . . . . . . . 14
⊢ (𝑧 = 𝑦 → (𝑥𝐹𝑧 ↔ 𝑥𝐹𝑦)) |
| 28 | 27 | cbviotavw 6522 |
. . . . . . . . . . . . 13
⊢
(℩𝑧𝑥𝐹𝑧) = (℩𝑦𝑥𝐹𝑦) |
| 29 | 28 | eqeq1i 2742 |
. . . . . . . . . . . 12
⊢
((℩𝑧𝑥𝐹𝑧) = 𝑧 ↔ (℩𝑦𝑥𝐹𝑦) = 𝑧) |
| 30 | 26, 29 | bitr2di 288 |
. . . . . . . . . . 11
⊢
(∃!𝑧 𝑥𝐹𝑧 → ((℩𝑦𝑥𝐹𝑦) = 𝑧 ↔ 𝑥𝐹𝑧)) |
| 31 | 25, 30 | syl 17 |
. . . . . . . . . 10
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ((℩𝑦𝑥𝐹𝑦) = 𝑧 ↔ 𝑥𝐹𝑧)) |
| 32 | 13, 17, 31 | vtocl 3558 |
. . . . . . . . 9
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ((℩𝑦𝑥𝐹𝑦) = (℩𝑦𝑥𝐹𝑦) ↔ 𝑥𝐹(℩𝑦𝑥𝐹𝑦))) |
| 33 | 12, 32 | mpbii 233 |
. . . . . . . 8
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → 𝑥𝐹(℩𝑦𝑥𝐹𝑦)) |
| 34 | | df-br 5144 |
. . . . . . . 8
⊢ (𝑥𝐹(℩𝑦𝑥𝐹𝑦) ↔ 〈𝑥, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹) |
| 35 | 33, 34 | sylib 218 |
. . . . . . 7
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → 〈𝑥, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹) |
| 36 | | vex 3484 |
. . . . . . . 8
⊢ 𝑥 ∈ V |
| 37 | | opeq1 4873 |
. . . . . . . . 9
⊢ (𝑧 = 𝑥 → 〈𝑧, (℩𝑦𝑥𝐹𝑦)〉 = 〈𝑥, (℩𝑦𝑥𝐹𝑦)〉) |
| 38 | 37 | eleq1d 2826 |
. . . . . . . 8
⊢ (𝑧 = 𝑥 → (〈𝑧, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹 ↔ 〈𝑥, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹)) |
| 39 | 36, 38 | spcev 3606 |
. . . . . . 7
⊢
(〈𝑥,
(℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹 → ∃𝑧〈𝑧, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹) |
| 40 | 35, 39 | syl 17 |
. . . . . 6
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → ∃𝑧〈𝑧, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹) |
| 41 | 13 | elrn2 5903 |
. . . . . 6
⊢
((℩𝑦𝑥𝐹𝑦) ∈ ran 𝐹 ↔ ∃𝑧〈𝑧, (℩𝑦𝑥𝐹𝑦)〉 ∈ 𝐹) |
| 42 | 40, 41 | sylibr 234 |
. . . . 5
⊢ ((Fun
(𝐹 ↾ {𝑥}) ∧ 𝑥 ∈ dom 𝐹) → (℩𝑦𝑥𝐹𝑦) ∈ ran 𝐹) |
| 43 | 11, 42 | vtoclg 3554 |
. . . 4
⊢ (𝐴 ∈ dom 𝐹 → ((Fun (𝐹 ↾ {𝐴}) ∧ 𝐴 ∈ dom 𝐹) → (℩𝑦𝐴𝐹𝑦) ∈ ran 𝐹)) |
| 44 | 43 | anabsi6 670 |
. . 3
⊢ ((𝐴 ∈ dom 𝐹 ∧ Fun (𝐹 ↾ {𝐴})) → (℩𝑦𝐴𝐹𝑦) ∈ ran 𝐹) |
| 45 | 2, 44 | sylbi 217 |
. 2
⊢ (𝐹 defAt 𝐴 → (℩𝑦𝐴𝐹𝑦) ∈ ran 𝐹) |
| 46 | 1, 45 | eqeltrd 2841 |
1
⊢ (𝐹 defAt 𝐴 → (𝐹''''𝐴) ∈ ran 𝐹) |