Proof of Theorem rnuni
| Step | Hyp | Ref
| Expression |
| 1 | | eluni 1922 |
. . . . . 6
⊢ (〈y, z〉
∈ ∪A ↔
∃x(〈y, z〉
∈ x ∧ x ∈ A)) |
| 2 | 1 | biex 733 |
. . . . 5
⊢ (∃y〈y,
z〉 ∈ ∪A ↔
∃y∃x(〈y,
z〉 ∈ x ∧ x ∈
A)) |
| 3 | | excom 728 |
. . . . 5
⊢ (∃y∃x(〈y,
z〉 ∈ x ∧ x ∈
A) ↔ ∃x∃y(〈y,
z〉 ∈ x ∧ x ∈
A)) |
| 4 | | ancom 333 |
. . . . . . 7
⊢ ((∃y〈y,
z〉 ∈ x ∧ x ∈
A) ↔ (x ∈ A ∧
∃y〈y, z〉
∈ x)) |
| 5 | | 19.41v 963 |
. . . . . . 7
⊢ (∃y(〈y,
z〉 ∈ x ∧ x ∈
A) ↔ (∃y〈y,
z〉 ∈ x ∧ x ∈
A)) |
| 6 | | visset 1350 |
. . . . . . . . 9
⊢ z
∈ V |
| 7 | 6 | elrn 2562 |
. . . . . . . 8
⊢ (z
∈ ran x ↔ ∃y〈y,
z〉 ∈ x) |
| 8 | 7 | anbi2i 367 |
. . . . . . 7
⊢ ((x
∈ A ∧ z ∈ ran x)
↔ (x ∈ A ∧ ∃y〈y,
z〉 ∈ x)) |
| 9 | 4, 5, 8 | 3bitr4 158 |
. . . . . 6
⊢ (∃y(〈y,
z〉 ∈ x ∧ x ∈
A) ↔ (x ∈ A ∧
z ∈ ran x)) |
| 10 | 9 | biex 733 |
. . . . 5
⊢ (∃x∃y(〈y,
z〉 ∈ x ∧ x ∈
A) ↔ ∃x(x ∈
A ∧ z ∈ ran x)) |
| 11 | 2, 3, 10 | 3bitr 155 |
. . . 4
⊢ (∃y〈y,
z〉 ∈ ∪A ↔
∃x(x ∈ A ∧
z ∈ ran x)) |
| 12 | | df-rex 1206 |
. . . 4
⊢ (∃x ∈ A
z ∈ ran x ↔ ∃x(x ∈
A ∧ z ∈ ran x)) |
| 13 | 11, 12 | bitr4 154 |
. . 3
⊢ (∃y〈y,
z〉 ∈ ∪A ↔
∃x ∈ A z ∈ ran
x) |
| 14 | 6 | elrn 2562 |
. . 3
⊢ (z
∈ ran ∪A
↔ ∃y〈y, z〉
∈ ∪A) |
| 15 | | eliun 1998 |
. . 3
⊢ (z
∈ ∪x ∈
A ran x
↔ ∃x ∈ A z ∈ ran
x) |
| 16 | 13, 14, 15 | 3bitr4 158 |
. 2
⊢ (z
∈ ran ∪A
↔ z ∈ ∪x ∈ A ran x) |
| 17 | 16 | cleqri 1101 |
1
⊢ ran ∪A = ∪x ∈ A ran
x |