| Step | Hyp | Ref
 | Expression | 
| 1 |   | simpll 527 | 
. . 3
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) →
EXMID) | 
| 2 |   | simprll 537 | 
. . 3
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → dom 𝑔 = 𝐵) | 
| 3 |   | simprlr 538 | 
. . 3
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → ran 𝑔 ⊆ 𝐴) | 
| 4 |   | simprr 531 | 
. . 3
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → Fun ◡𝑔) | 
| 5 |   | rnun 5078 | 
. . . . 5
⊢ ran
((𝑓 ↾ ∪ 𝐷)
∪ (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) = (ran (𝑓 ↾ ∪ 𝐷) ∪ ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 6 |   | sbthlem.3 | 
. . . . . 6
⊢ 𝐻 = ((𝑓 ↾ ∪ 𝐷) ∪ (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 7 | 6 | rneqi 4894 | 
. . . . 5
⊢ ran 𝐻 = ran ((𝑓 ↾ ∪ 𝐷) ∪ (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 8 |   | df-ima 4676 | 
. . . . . 6
⊢ (𝑓 “ ∪ 𝐷) =
ran (𝑓 ↾ ∪ 𝐷) | 
| 9 | 8 | uneq1i 3313 | 
. . . . 5
⊢ ((𝑓 “ ∪ 𝐷)
∪ ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) = (ran (𝑓 ↾ ∪ 𝐷) ∪ ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 10 | 5, 7, 9 | 3eqtr4i 2227 | 
. . . 4
⊢ ran 𝐻 = ((𝑓 “ ∪ 𝐷) ∪ ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 11 |   | sbthlem.1 | 
. . . . . . 7
⊢ 𝐴 ∈ V | 
| 12 |   | sbthlem.2 | 
. . . . . . 7
⊢ 𝐷 = {𝑥 ∣ (𝑥 ⊆ 𝐴 ∧ (𝑔 “ (𝐵 ∖ (𝑓 “ 𝑥))) ⊆ (𝐴 ∖ 𝑥))} | 
| 13 | 11, 12 | sbthlemi4 7026 | 
. . . . . 6
⊢
((EXMID ∧ (dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔) → (◡𝑔 “ (𝐴 ∖ ∪ 𝐷)) = (𝐵 ∖ (𝑓 “ ∪ 𝐷))) | 
| 14 |   | df-ima 4676 | 
. . . . . 6
⊢ (◡𝑔 “ (𝐴 ∖ ∪ 𝐷)) = ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷)) | 
| 15 | 13, 14 | eqtr3di 2244 | 
. . . . 5
⊢
((EXMID ∧ (dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔) → (𝐵 ∖ (𝑓 “ ∪ 𝐷)) = ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷))) | 
| 16 | 15 | uneq2d 3317 | 
. . . 4
⊢
((EXMID ∧ (dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔) → ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) = ((𝑓 “ ∪ 𝐷) ∪ ran (◡𝑔 ↾ (𝐴 ∖ ∪ 𝐷)))) | 
| 17 | 10, 16 | eqtr4id 2248 | 
. . 3
⊢
((EXMID ∧ (dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔) → ran 𝐻 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷)))) | 
| 18 | 1, 2, 3, 4, 17 | syl121anc 1254 | 
. 2
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → ran 𝐻 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷)))) | 
| 19 |   | imassrn 5020 | 
. . . . . . 7
⊢ (𝑓 “ ∪ 𝐷)
⊆ ran 𝑓 | 
| 20 |   | sstr2 3190 | 
. . . . . . 7
⊢ ((𝑓 “ ∪ 𝐷)
⊆ ran 𝑓 → (ran
𝑓 ⊆ 𝐵 → (𝑓 “ ∪ 𝐷) ⊆ 𝐵)) | 
| 21 | 19, 20 | ax-mp 5 | 
. . . . . 6
⊢ (ran
𝑓 ⊆ 𝐵 → (𝑓 “ ∪ 𝐷) ⊆ 𝐵) | 
| 22 | 21 | adantl 277 | 
. . . . 5
⊢
((EXMID ∧ ran 𝑓 ⊆ 𝐵) → (𝑓 “ ∪ 𝐷) ⊆ 𝐵) | 
| 23 |   | undifdcss 6984 | 
. . . . . . 7
⊢ (𝐵 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) ↔ ((𝑓 “ ∪ 𝐷) ⊆ 𝐵 ∧ ∀𝑦 ∈ 𝐵 DECID 𝑦 ∈ (𝑓 “ ∪ 𝐷))) | 
| 24 |   | exmidexmid 4229 | 
. . . . . . . . 9
⊢
(EXMID → DECID 𝑦 ∈ (𝑓 “ ∪ 𝐷)) | 
| 25 | 24 | ralrimivw 2571 | 
. . . . . . . 8
⊢
(EXMID → ∀𝑦 ∈ 𝐵 DECID 𝑦 ∈ (𝑓 “ ∪ 𝐷)) | 
| 26 | 25 | biantrud 304 | 
. . . . . . 7
⊢
(EXMID → ((𝑓 “ ∪ 𝐷) ⊆ 𝐵 ↔ ((𝑓 “ ∪ 𝐷) ⊆ 𝐵 ∧ ∀𝑦 ∈ 𝐵 DECID 𝑦 ∈ (𝑓 “ ∪ 𝐷)))) | 
| 27 | 23, 26 | bitr4id 199 | 
. . . . . 6
⊢
(EXMID → (𝐵 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) ↔ (𝑓 “ ∪ 𝐷) ⊆ 𝐵)) | 
| 28 | 27 | adantr 276 | 
. . . . 5
⊢
((EXMID ∧ ran 𝑓 ⊆ 𝐵) → (𝐵 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) ↔ (𝑓 “ ∪ 𝐷) ⊆ 𝐵)) | 
| 29 | 22, 28 | mpbird 167 | 
. . . 4
⊢
((EXMID ∧ ran 𝑓 ⊆ 𝐵) → 𝐵 = ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷)))) | 
| 30 | 29 | eqcomd 2202 | 
. . 3
⊢
((EXMID ∧ ran 𝑓 ⊆ 𝐵) → ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) = 𝐵) | 
| 31 | 30 | adantr 276 | 
. 2
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → ((𝑓 “ ∪ 𝐷) ∪ (𝐵 ∖ (𝑓 “ ∪ 𝐷))) = 𝐵) | 
| 32 | 18, 31 | eqtrd 2229 | 
1
⊢
(((EXMID ∧ ran 𝑓 ⊆ 𝐵) ∧ ((dom 𝑔 = 𝐵 ∧ ran 𝑔 ⊆ 𝐴) ∧ Fun ◡𝑔)) → ran 𝐻 = 𝐵) |