| Step | Hyp | Ref
 | Expression | 
| 1 |   | inss2 3384 | 
. . . . 5
⊢ (𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐴 × 𝐵) | 
| 2 |   | rnss 4896 | 
. . . . 5
⊢ ((𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐴 × 𝐵) → ran (𝐶 ∩ (𝐴 × 𝐵)) ⊆ ran (𝐴 × 𝐵)) | 
| 3 | 1, 2 | ax-mp 5 | 
. . . 4
⊢ ran
(𝐶 ∩ (𝐴 × 𝐵)) ⊆ ran (𝐴 × 𝐵) | 
| 4 |   | rnxpss 5101 | 
. . . 4
⊢ ran
(𝐴 × 𝐵) ⊆ 𝐵 | 
| 5 | 3, 4 | sstri 3192 | 
. . 3
⊢ ran
(𝐶 ∩ (𝐴 × 𝐵)) ⊆ 𝐵 | 
| 6 |   | eqss 3198 | 
. . 3
⊢ (ran
(𝐶 ∩ (𝐴 × 𝐵)) = 𝐵 ↔ (ran (𝐶 ∩ (𝐴 × 𝐵)) ⊆ 𝐵 ∧ 𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵)))) | 
| 7 | 5, 6 | mpbiran 942 | 
. 2
⊢ (ran
(𝐶 ∩ (𝐴 × 𝐵)) = 𝐵 ↔ 𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵))) | 
| 8 |   | ssid 3203 | 
. . . . . . . 8
⊢ 𝐴 ⊆ 𝐴 | 
| 9 |   | ssv 3205 | 
. . . . . . . 8
⊢ 𝐵 ⊆ V | 
| 10 |   | xpss12 4770 | 
. . . . . . . 8
⊢ ((𝐴 ⊆ 𝐴 ∧ 𝐵 ⊆ V) → (𝐴 × 𝐵) ⊆ (𝐴 × V)) | 
| 11 | 8, 9, 10 | mp2an 426 | 
. . . . . . 7
⊢ (𝐴 × 𝐵) ⊆ (𝐴 × V) | 
| 12 |   | sslin 3389 | 
. . . . . . 7
⊢ ((𝐴 × 𝐵) ⊆ (𝐴 × V) → (𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐶 ∩ (𝐴 × V))) | 
| 13 | 11, 12 | ax-mp 5 | 
. . . . . 6
⊢ (𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐶 ∩ (𝐴 × V)) | 
| 14 |   | df-res 4675 | 
. . . . . 6
⊢ (𝐶 ↾ 𝐴) = (𝐶 ∩ (𝐴 × V)) | 
| 15 | 13, 14 | sseqtrri 3218 | 
. . . . 5
⊢ (𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐶 ↾ 𝐴) | 
| 16 |   | rnss 4896 | 
. . . . 5
⊢ ((𝐶 ∩ (𝐴 × 𝐵)) ⊆ (𝐶 ↾ 𝐴) → ran (𝐶 ∩ (𝐴 × 𝐵)) ⊆ ran (𝐶 ↾ 𝐴)) | 
| 17 | 15, 16 | ax-mp 5 | 
. . . 4
⊢ ran
(𝐶 ∩ (𝐴 × 𝐵)) ⊆ ran (𝐶 ↾ 𝐴) | 
| 18 |   | sstr 3191 | 
. . . 4
⊢ ((𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵)) ∧ ran (𝐶 ∩ (𝐴 × 𝐵)) ⊆ ran (𝐶 ↾ 𝐴)) → 𝐵 ⊆ ran (𝐶 ↾ 𝐴)) | 
| 19 | 17, 18 | mpan2 425 | 
. . 3
⊢ (𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵)) → 𝐵 ⊆ ran (𝐶 ↾ 𝐴)) | 
| 20 |   | ssel 3177 | 
. . . . . . 7
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) → (𝑦 ∈ 𝐵 → 𝑦 ∈ ran (𝐶 ↾ 𝐴))) | 
| 21 |   | vex 2766 | 
. . . . . . . 8
⊢ 𝑦 ∈ V | 
| 22 | 21 | elrn2 4908 | 
. . . . . . 7
⊢ (𝑦 ∈ ran (𝐶 ↾ 𝐴) ↔ ∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴)) | 
| 23 | 20, 22 | imbitrdi 161 | 
. . . . . 6
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) → (𝑦 ∈ 𝐵 → ∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴))) | 
| 24 | 23 | ancrd 326 | 
. . . . 5
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) → (𝑦 ∈ 𝐵 → (∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵))) | 
| 25 | 21 | elrn2 4908 | 
. . . . . 6
⊢ (𝑦 ∈ ran (𝐶 ∩ (𝐴 × 𝐵)) ↔ ∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ∩ (𝐴 × 𝐵))) | 
| 26 |   | elin 3346 | 
. . . . . . . 8
⊢
(〈𝑥, 𝑦〉 ∈ (𝐶 ∩ (𝐴 × 𝐵)) ↔ (〈𝑥, 𝑦〉 ∈ 𝐶 ∧ 〈𝑥, 𝑦〉 ∈ (𝐴 × 𝐵))) | 
| 27 |   | opelxp 4693 | 
. . . . . . . . 9
⊢
(〈𝑥, 𝑦〉 ∈ (𝐴 × 𝐵) ↔ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) | 
| 28 | 27 | anbi2i 457 | 
. . . . . . . 8
⊢
((〈𝑥, 𝑦〉 ∈ 𝐶 ∧ 〈𝑥, 𝑦〉 ∈ (𝐴 × 𝐵)) ↔ (〈𝑥, 𝑦〉 ∈ 𝐶 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵))) | 
| 29 | 21 | opelres 4951 | 
. . . . . . . . . 10
⊢
(〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ↔ (〈𝑥, 𝑦〉 ∈ 𝐶 ∧ 𝑥 ∈ 𝐴)) | 
| 30 | 29 | anbi1i 458 | 
. . . . . . . . 9
⊢
((〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵) ↔ ((〈𝑥, 𝑦〉 ∈ 𝐶 ∧ 𝑥 ∈ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 31 |   | anass 401 | 
. . . . . . . . 9
⊢
(((〈𝑥, 𝑦〉 ∈ 𝐶 ∧ 𝑥 ∈ 𝐴) ∧ 𝑦 ∈ 𝐵) ↔ (〈𝑥, 𝑦〉 ∈ 𝐶 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵))) | 
| 32 | 30, 31 | bitr2i 185 | 
. . . . . . . 8
⊢
((〈𝑥, 𝑦〉 ∈ 𝐶 ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) ↔ (〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 33 | 26, 28, 32 | 3bitri 206 | 
. . . . . . 7
⊢
(〈𝑥, 𝑦〉 ∈ (𝐶 ∩ (𝐴 × 𝐵)) ↔ (〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 34 | 33 | exbii 1619 | 
. . . . . 6
⊢
(∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ∩ (𝐴 × 𝐵)) ↔ ∃𝑥(〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 35 |   | 19.41v 1917 | 
. . . . . 6
⊢
(∃𝑥(〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵) ↔ (∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 36 | 25, 34, 35 | 3bitri 206 | 
. . . . 5
⊢ (𝑦 ∈ ran (𝐶 ∩ (𝐴 × 𝐵)) ↔ (∃𝑥〈𝑥, 𝑦〉 ∈ (𝐶 ↾ 𝐴) ∧ 𝑦 ∈ 𝐵)) | 
| 37 | 24, 36 | imbitrrdi 162 | 
. . . 4
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) → (𝑦 ∈ 𝐵 → 𝑦 ∈ ran (𝐶 ∩ (𝐴 × 𝐵)))) | 
| 38 | 37 | ssrdv 3189 | 
. . 3
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) → 𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵))) | 
| 39 | 19, 38 | impbii 126 | 
. 2
⊢ (𝐵 ⊆ ran (𝐶 ∩ (𝐴 × 𝐵)) ↔ 𝐵 ⊆ ran (𝐶 ↾ 𝐴)) | 
| 40 | 7, 39 | bitr2i 185 | 
1
⊢ (𝐵 ⊆ ran (𝐶 ↾ 𝐴) ↔ ran (𝐶 ∩ (𝐴 × 𝐵)) = 𝐵) |