Proof of Theorem rabun2
Step | Hyp | Ref
| Expression |
1 | | df-rab 2624 |
. 2
⊢ {x ∈ (A ∪ B) ∣ φ} =
{x ∣
(x ∈
(A ∪ B) ∧ φ)} |
2 | | df-rab 2624 |
. . . 4
⊢ {x ∈ A ∣ φ} = {x
∣ (x
∈ A ∧ φ)} |
3 | | df-rab 2624 |
. . . 4
⊢ {x ∈ B ∣ φ} = {x
∣ (x
∈ B ∧ φ)} |
4 | 2, 3 | uneq12i 3417 |
. . 3
⊢ ({x ∈ A ∣ φ} ∪ {x ∈ B ∣ φ}) = ({x
∣ (x
∈ A ∧ φ)} ∪
{x ∣
(x ∈
B ∧ φ)}) |
5 | | elun 3221 |
. . . . . . 7
⊢ (x ∈ (A ∪ B)
↔ (x ∈ A ∨ x ∈ B)) |
6 | 5 | anbi1i 676 |
. . . . . 6
⊢ ((x ∈ (A ∪ B) ∧ φ) ↔
((x ∈
A ∨
x ∈
B) ∧ φ)) |
7 | | andir 838 |
. . . . . 6
⊢ (((x ∈ A ∨ x ∈ B) ∧ φ) ↔ ((x ∈ A ∧ φ) ∨
(x ∈
B ∧ φ))) |
8 | 6, 7 | bitri 240 |
. . . . 5
⊢ ((x ∈ (A ∪ B) ∧ φ) ↔
((x ∈
A ∧ φ) ∨
(x ∈
B ∧ φ))) |
9 | 8 | abbii 2466 |
. . . 4
⊢ {x ∣ (x ∈ (A ∪ B) ∧ φ)} =
{x ∣
((x ∈
A ∧ φ) ∨
(x ∈
B ∧ φ))} |
10 | | unab 3522 |
. . . 4
⊢ ({x ∣ (x ∈ A ∧ φ)} ∪ {x ∣ (x ∈ B ∧ φ)}) = {x
∣ ((x
∈ A ∧ φ) ∨ (x ∈ B ∧ φ))} |
11 | 9, 10 | eqtr4i 2376 |
. . 3
⊢ {x ∣ (x ∈ (A ∪ B) ∧ φ)} =
({x ∣
(x ∈
A ∧ φ)} ∪ {x ∣ (x ∈ B ∧ φ)}) |
12 | 4, 11 | eqtr4i 2376 |
. 2
⊢ ({x ∈ A ∣ φ} ∪ {x ∈ B ∣ φ}) = {x
∣ (x
∈ (A
∪ B) ∧
φ)} |
13 | 1, 12 | eqtr4i 2376 |
1
⊢ {x ∈ (A ∪ B) ∣ φ} =
({x ∈
A ∣
φ} ∪ {x ∈ B ∣ φ}) |