| Step | Hyp | Ref
 | Expression | 
| 1 |   | imainlem 5339 | 
. . 3
⊢ (𝐹 “ (𝐴 ∩ 𝐵)) ⊆ ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵)) | 
| 2 | 1 | a1i 9 | 
. 2
⊢ (Fun
◡𝐹 → (𝐹 “ (𝐴 ∩ 𝐵)) ⊆ ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵))) | 
| 3 |   | eeanv 1951 | 
. . . . . 6
⊢
(∃𝑥∃𝑧((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) ↔ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ ∃𝑧(𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) | 
| 4 |   | simprll 537 | 
. . . . . . . . . . 11
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑥 ∈ 𝐴) | 
| 5 |   | simpr 110 | 
. . . . . . . . . . . . . 14
⊢ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) → 𝑥𝐹𝑦) | 
| 6 |   | simpr 110 | 
. . . . . . . . . . . . . 14
⊢ ((𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦) → 𝑧𝐹𝑦) | 
| 7 | 5, 6 | anim12i 338 | 
. . . . . . . . . . . . 13
⊢ (((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) → (𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦)) | 
| 8 |   | funcnveq 5321 | 
. . . . . . . . . . . . . . . . 17
⊢ (Fun
◡𝐹 ↔ ∀𝑥∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦) → 𝑥 = 𝑧)) | 
| 9 | 8 | biimpi 120 | 
. . . . . . . . . . . . . . . 16
⊢ (Fun
◡𝐹 → ∀𝑥∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦) → 𝑥 = 𝑧)) | 
| 10 | 9 | 19.21bi 1572 | 
. . . . . . . . . . . . . . 15
⊢ (Fun
◡𝐹 → ∀𝑦∀𝑧((𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦) → 𝑥 = 𝑧)) | 
| 11 | 10 | 19.21bbi 1573 | 
. . . . . . . . . . . . . 14
⊢ (Fun
◡𝐹 → ((𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦) → 𝑥 = 𝑧)) | 
| 12 | 11 | imp 124 | 
. . . . . . . . . . . . 13
⊢ ((Fun
◡𝐹 ∧ (𝑥𝐹𝑦 ∧ 𝑧𝐹𝑦)) → 𝑥 = 𝑧) | 
| 13 | 7, 12 | sylan2 286 | 
. . . . . . . . . . . 12
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑥 = 𝑧) | 
| 14 |   | simprrl 539 | 
. . . . . . . . . . . 12
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑧 ∈ 𝐵) | 
| 15 | 13, 14 | eqeltrd 2273 | 
. . . . . . . . . . 11
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑥 ∈ 𝐵) | 
| 16 |   | elin 3346 | 
. . . . . . . . . . 11
⊢ (𝑥 ∈ (𝐴 ∩ 𝐵) ↔ (𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)) | 
| 17 | 4, 15, 16 | sylanbrc 417 | 
. . . . . . . . . 10
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑥 ∈ (𝐴 ∩ 𝐵)) | 
| 18 |   | simprlr 538 | 
. . . . . . . . . 10
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → 𝑥𝐹𝑦) | 
| 19 | 17, 18 | jca 306 | 
. . . . . . . . 9
⊢ ((Fun
◡𝐹 ∧ ((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) → (𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦)) | 
| 20 | 19 | ex 115 | 
. . . . . . . 8
⊢ (Fun
◡𝐹 → (((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) → (𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦))) | 
| 21 | 20 | exlimdv 1833 | 
. . . . . . 7
⊢ (Fun
◡𝐹 → (∃𝑧((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) → (𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦))) | 
| 22 | 21 | eximdv 1894 | 
. . . . . 6
⊢ (Fun
◡𝐹 → (∃𝑥∃𝑧((𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ (𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) → ∃𝑥(𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦))) | 
| 23 | 3, 22 | biimtrrid 153 | 
. . . . 5
⊢ (Fun
◡𝐹 → ((∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ ∃𝑧(𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) → ∃𝑥(𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦))) | 
| 24 |   | df-rex 2481 | 
. . . . . 6
⊢
(∃𝑥 ∈
𝐴 𝑥𝐹𝑦 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦)) | 
| 25 |   | df-rex 2481 | 
. . . . . 6
⊢
(∃𝑧 ∈
𝐵 𝑧𝐹𝑦 ↔ ∃𝑧(𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦)) | 
| 26 | 24, 25 | anbi12i 460 | 
. . . . 5
⊢
((∃𝑥 ∈
𝐴 𝑥𝐹𝑦 ∧ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦) ↔ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥𝐹𝑦) ∧ ∃𝑧(𝑧 ∈ 𝐵 ∧ 𝑧𝐹𝑦))) | 
| 27 |   | df-rex 2481 | 
. . . . 5
⊢
(∃𝑥 ∈
(𝐴 ∩ 𝐵)𝑥𝐹𝑦 ↔ ∃𝑥(𝑥 ∈ (𝐴 ∩ 𝐵) ∧ 𝑥𝐹𝑦)) | 
| 28 | 23, 26, 27 | 3imtr4g 205 | 
. . . 4
⊢ (Fun
◡𝐹 → ((∃𝑥 ∈ 𝐴 𝑥𝐹𝑦 ∧ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦) → ∃𝑥 ∈ (𝐴 ∩ 𝐵)𝑥𝐹𝑦)) | 
| 29 | 28 | ss2abdv 3256 | 
. . 3
⊢ (Fun
◡𝐹 → {𝑦 ∣ (∃𝑥 ∈ 𝐴 𝑥𝐹𝑦 ∧ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦)} ⊆ {𝑦 ∣ ∃𝑥 ∈ (𝐴 ∩ 𝐵)𝑥𝐹𝑦}) | 
| 30 |   | dfima2 5011 | 
. . . . 5
⊢ (𝐹 “ 𝐴) = {𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑥𝐹𝑦} | 
| 31 |   | dfima2 5011 | 
. . . . 5
⊢ (𝐹 “ 𝐵) = {𝑦 ∣ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦} | 
| 32 | 30, 31 | ineq12i 3362 | 
. . . 4
⊢ ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵)) = ({𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑥𝐹𝑦} ∩ {𝑦 ∣ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦}) | 
| 33 |   | inab 3431 | 
. . . 4
⊢ ({𝑦 ∣ ∃𝑥 ∈ 𝐴 𝑥𝐹𝑦} ∩ {𝑦 ∣ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦}) = {𝑦 ∣ (∃𝑥 ∈ 𝐴 𝑥𝐹𝑦 ∧ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦)} | 
| 34 | 32, 33 | eqtri 2217 | 
. . 3
⊢ ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵)) = {𝑦 ∣ (∃𝑥 ∈ 𝐴 𝑥𝐹𝑦 ∧ ∃𝑧 ∈ 𝐵 𝑧𝐹𝑦)} | 
| 35 |   | dfima2 5011 | 
. . 3
⊢ (𝐹 “ (𝐴 ∩ 𝐵)) = {𝑦 ∣ ∃𝑥 ∈ (𝐴 ∩ 𝐵)𝑥𝐹𝑦} | 
| 36 | 29, 34, 35 | 3sstr4g 3226 | 
. 2
⊢ (Fun
◡𝐹 → ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵)) ⊆ (𝐹 “ (𝐴 ∩ 𝐵))) | 
| 37 | 2, 36 | eqssd 3200 | 
1
⊢ (Fun
◡𝐹 → (𝐹 “ (𝐴 ∩ 𝐵)) = ((𝐹 “ 𝐴) ∩ (𝐹 “ 𝐵))) |