Proof of Theorem uniiunlem
| Step | Hyp | Ref
| Expression |
| 1 | | hbra1 1690 |
. . . . 5
⊢ (∀x ∈ A B ∈ C → ∀x∀x ∈ A B ∈ C) |
| 2 | | ax-17 973 |
. . . . 5
⊢ (z ∈ C → ∀x z ∈ C) |
| 3 | | ra4 1697 |
. . . . . 6
⊢ (∀x ∈ A B ∈ C → (x
∈ A
→ B ∈ C)) |
| 4 | | eleq1a 1546 |
. . . . . 6
⊢ (B ∈ C → (z =
B → z ∈ C)) |
| 5 | 3, 4 | syl6 22 |
. . . . 5
⊢ (∀x ∈ A B ∈ C → (x
∈ A
→ (z = B → z ∈ C))) |
| 6 | 1, 2, 5 | r19.23ad 1748 |
. . . 4
⊢ (∀x ∈ A B ∈ C → (∃x ∈ A z = B →
z ∈
C)) |
| 7 | 6 | 19.21aiv 1288 |
. . 3
⊢ (∀x ∈ A B ∈ C → ∀z(∃x ∈ A z = B →
z ∈
C)) |
| 8 | | hbre1 1692 |
. . . . . . 7
⊢ (∃x ∈ A z = B →
∀x∃x ∈ A z = B) |
| 9 | 8, 2 | hbim 1009 |
. . . . . 6
⊢ ((∃x ∈ A z = B →
z ∈
C) → ∀x(∃x ∈ A z = B →
z ∈
C)) |
| 10 | 9 | hbal 1007 |
. . . . 5
⊢ (∀z(∃x ∈ A z = B →
z ∈
C) → ∀x∀z(∃x ∈ A z = B →
z ∈
C)) |
| 11 | | csbeq1a 2009 |
. . . . . . . . . . . 12
⊢ (x = w →
B = [w / x]B) |
| 12 | 11 | eqcoms 1481 |
. . . . . . . . . . 11
⊢ (w = x →
B = [w / x]B) |
| 13 | 12 | eqcomd 1483 |
. . . . . . . . . 10
⊢ (w = x →
[w / x]B =
B) |
| 14 | 13 | eqeq1d 1486 |
. . . . . . . . 9
⊢ (w = x →
([w / x]B =
B ↔ B = B)) |
| 15 | | eqid 1478 |
. . . . . . . . 9
⊢ B = B |
| 16 | 14, 15 | a4eiv 1276 |
. . . . . . . 8
⊢ ∃w[w /
x]B = B |
| 17 | | visset 1816 |
. . . . . . . . . . . . . . . . . 18
⊢ w ∈
V |
| 18 | | ax-17 973 |
. . . . . . . . . . . . . . . . . 18
⊢ (z ∈ w → ∀x z ∈ w) |
| 19 | 17, 18 | hbcsb1 2028 |
. . . . . . . . . . . . . . . . 17
⊢ (z ∈
[w / x]B
→ ∀x z ∈ [w /
x]B) |
| 20 | 19 | hbeleq 1570 |
. . . . . . . . . . . . . . . 16
⊢ (z = [w /
x]B → ∀x z = [w /
x]B) |
| 21 | | eqeq1 1484 |
. . . . . . . . . . . . . . . 16
⊢ (z = [w /
x]B → (z =
B ↔ [w / x]B =
B)) |
| 22 | 20, 21 | rexbid 1665 |
. . . . . . . . . . . . . . 15
⊢ (z = [w /
x]B → (∃x ∈ A z = B ↔
∃x ∈ A
[w / x]B =
B)) |
| 23 | | eleq1 1537 |
. . . . . . . . . . . . . . 15
⊢ (z = [w /
x]B → (z
∈ C
↔ [w / x]B ∈ C)) |
| 24 | 22, 23 | imbi12d 628 |
. . . . . . . . . . . . . 14
⊢ (z = [w /
x]B → ((∃x ∈ A z = B →
z ∈
C) ↔ (∃x ∈ A
[w / x]B =
B → [w / x]B ∈ C))) |
| 25 | 24 | cla4gv 1865 |
. . . . . . . . . . . . 13
⊢ ([w / x]B ∈ D →
(∀z(∃x ∈ A z = B → z ∈ C) →
(∃x
∈ A
[w / x]B =
B → [w / x]B ∈ C))) |
| 26 | | ra4e 1698 |
. . . . . . . . . . . . 13
⊢ ((x ∈ A ⋀
[w / x]B =
B) → ∃x ∈ A
[w / x]B =
B) |
| 27 | 25, 26 | syl7 23 |
. . . . . . . . . . . 12
⊢ ([w / x]B ∈ D →
(∀z(∃x ∈ A z = B → z ∈ C) →
((x ∈
A ⋀
[w / x]B =
B) → [w / x]B ∈ C))) |
| 28 | 27 | exp4a 380 |
. . . . . . . . . . 11
⊢ ([w / x]B ∈ D →
(∀z(∃x ∈ A z = B → z ∈ C) →
(x ∈
A → ([w / x]B =
B → [w / x]B ∈ C)))) |
| 29 | 28 | com4r 41 |
. . . . . . . . . 10
⊢ ([w / x]B =
B → ([w / x]B ∈ D →
(∀z(∃x ∈ A z = B → z ∈ C) →
(x ∈
A → [w / x]B ∈ C)))) |
| 30 | | eleq1 1537 |
. . . . . . . . . 10
⊢ ([w / x]B =
B → ([w / x]B ∈ D ↔
B ∈
D)) |
| 31 | | eleq1 1537 |
. . . . . . . . . . . 12
⊢ ([w / x]B =
B → ([w / x]B ∈ C ↔
B ∈
C)) |
| 32 | 31 | imbi2d 614 |
. . . . . . . . . . 11
⊢ ([w / x]B =
B → ((x ∈ A → [w / x]B ∈ C) ↔
(x ∈
A → B ∈ C))) |
| 33 | 32 | imbi2d 614 |
. . . . . . . . . 10
⊢ ([w / x]B =
B → ((∀z(∃x ∈ A z = B →
z ∈
C) → (x ∈ A → [w / x]B ∈ C)) ↔
(∀z(∃x ∈ A z = B → z ∈ C) →
(x ∈
A → B ∈ C)))) |
| 34 | 29, 30, 33 | 3imtr3d 544 |
. . . . . . . . 9
⊢ ([w / x]B =
B → (B ∈ D → (∀z(∃x ∈ A z = B →
z ∈
C) → (x ∈ A → B ∈ C)))) |
| 35 | 34 | 19.23aiv 1297 |
. . . . . . . 8
⊢ (∃w[w /
x]B = B →
(B ∈
D → (∀z(∃x ∈ A z = B →
z ∈
C) → (x ∈ A → B ∈ C)))) |
| 36 | 16, 35 | ax-mp 7 |
. . . . . . 7
⊢ (B ∈ D → (∀z(∃x ∈ A z = B →
z ∈
C) → (x ∈ A → B ∈ C))) |
| 37 | 36 | imp3a 361 |
. . . . . 6
⊢ (B ∈ D → ((∀z(∃x ∈ A z = B →
z ∈
C) ⋀
x ∈
A) → B ∈ C)) |
| 38 | 37 | com12 11 |
. . . . 5
⊢ ((∀z(∃x ∈ A z = B →
z ∈
C) ⋀
x ∈
A) → (B ∈ D → B ∈ C)) |
| 39 | 10, 38 | r19.20da 1711 |
. . . 4
⊢ (∀z(∃x ∈ A z = B →
z ∈
C) → (∀x ∈ A B ∈ D → ∀x ∈ A B ∈ C)) |
| 40 | 39 | com12 11 |
. . 3
⊢ (∀x ∈ A B ∈ D → (∀z(∃x ∈ A z = B →
z ∈
C) → ∀x ∈ A B ∈ C)) |
| 41 | 7, 40 | impbid2 520 |
. 2
⊢ (∀x ∈ A B ∈ D → (∀x ∈ A B ∈ C ↔ ∀z(∃x ∈ A z = B →
z ∈
C))) |
| 42 | | abss 2120 |
. . 3
⊢ ({z∣∃x ∈ A z = B} ⊆ C ↔
∀z(∃x ∈ A z = B → z ∈ C)) |
| 43 | | eqeq1 1484 |
. . . . . 6
⊢ (z = y →
(z = B
↔ y = B)) |
| 44 | 43 | rexbidv 1667 |
. . . . 5
⊢ (z = y →
(∃x
∈ A
z = B
↔ ∃x ∈ A y = B)) |
| 45 | 44 | cbvabv 1912 |
. . . 4
⊢ {z∣∃x ∈ A z = B} =
{y∣∃x ∈ A y = B} |
| 46 | 45 | sseq1i 2088 |
. . 3
⊢ ({z∣∃x ∈ A z = B} ⊆ C ↔
{y∣∃x ∈ A y = B} ⊆ C) |
| 47 | 42, 46 | bitr3 175 |
. 2
⊢ (∀z(∃x ∈ A z = B →
z ∈
C) ↔ {y∣∃x ∈ A y = B} ⊆ C) |
| 48 | 41, 47 | syl6bb 538 |
1
⊢ (∀x ∈ A B ∈ D → (∀x ∈ A B ∈ C ↔ {y∣∃x ∈ A y = B} ⊆ C)) |