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 ) ) ) |