| Step |
Hyp |
Ref |
Expression |
| 1 |
|
fvex |
⊢ ( 1st ‘ 𝐴 ) ∈ V |
| 2 |
|
fvex |
⊢ ( 2nd ‘ 𝐴 ) ∈ V |
| 3 |
1 2
|
unex |
⊢ ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) ∈ V |
| 4 |
3
|
isseti |
⊢ ∃ 𝑥 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) |
| 5 |
|
sseq1 |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 𝑥 ⊆ Pg ↔ ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) ⊆ Pg ) ) |
| 6 |
|
unss |
⊢ ( ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) ↔ ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) ⊆ Pg ) |
| 7 |
5 6
|
bitr4di |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 𝑥 ⊆ Pg ↔ ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) ) ) |
| 8 |
7
|
biimprd |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) → 𝑥 ⊆ Pg ) ) |
| 9 |
|
ssun1 |
⊢ ( 1st ‘ 𝐴 ) ⊆ ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) |
| 10 |
|
id |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) ) |
| 11 |
9 10
|
sseqtrrid |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 1st ‘ 𝐴 ) ⊆ 𝑥 ) |
| 12 |
|
vex |
⊢ 𝑥 ∈ V |
| 13 |
12
|
elpw2 |
⊢ ( ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ↔ ( 1st ‘ 𝐴 ) ⊆ 𝑥 ) |
| 14 |
11 13
|
sylibr |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ) |
| 15 |
|
ssun2 |
⊢ ( 2nd ‘ 𝐴 ) ⊆ ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) |
| 16 |
15 10
|
sseqtrrid |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 2nd ‘ 𝐴 ) ⊆ 𝑥 ) |
| 17 |
12
|
elpw2 |
⊢ ( ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ↔ ( 2nd ‘ 𝐴 ) ⊆ 𝑥 ) |
| 18 |
16 17
|
sylibr |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ) |
| 19 |
14 18
|
jca |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ∧ ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ) ) |
| 20 |
8 19
|
jctird |
⊢ ( 𝑥 = ( ( 1st ‘ 𝐴 ) ∪ ( 2nd ‘ 𝐴 ) ) → ( ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) → ( 𝑥 ⊆ Pg ∧ ( ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ∧ ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ) ) ) ) |
| 21 |
4 20
|
eximii |
⊢ ∃ 𝑥 ( ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) → ( 𝑥 ⊆ Pg ∧ ( ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ∧ ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ) ) ) |
| 22 |
21
|
19.37iv |
⊢ ( ( ( 1st ‘ 𝐴 ) ⊆ Pg ∧ ( 2nd ‘ 𝐴 ) ⊆ Pg ) → ∃ 𝑥 ( 𝑥 ⊆ Pg ∧ ( ( 1st ‘ 𝐴 ) ∈ 𝒫 𝑥 ∧ ( 2nd ‘ 𝐴 ) ∈ 𝒫 𝑥 ) ) ) |