Step |
Hyp |
Ref |
Expression |
1 |
|
elpwi |
⊢ ( 𝐴 ∈ 𝒫 𝐵 → 𝐴 ⊆ 𝐵 ) |
2 |
|
ssidd |
⊢ ( 𝐴 ⊆ 𝐵 → 𝐴 ⊆ 𝐴 ) |
3 |
|
id |
⊢ ( 𝐴 ⊆ 𝐵 → 𝐴 ⊆ 𝐵 ) |
4 |
2 3
|
ssind |
⊢ ( 𝐴 ⊆ 𝐵 → 𝐴 ⊆ ( 𝐴 ∩ 𝐵 ) ) |
5 |
|
ssexg |
⊢ ( ( 𝐴 ⊆ ( 𝐴 ∩ 𝐵 ) ∧ ( 𝐴 ∩ 𝐵 ) ∈ 𝑉 ) → 𝐴 ∈ V ) |
6 |
4 5
|
sylan |
⊢ ( ( 𝐴 ⊆ 𝐵 ∧ ( 𝐴 ∩ 𝐵 ) ∈ 𝑉 ) → 𝐴 ∈ V ) |
7 |
|
elpwg |
⊢ ( 𝐴 ∈ V → ( 𝐴 ∈ 𝒫 𝐵 ↔ 𝐴 ⊆ 𝐵 ) ) |
8 |
7
|
biimparc |
⊢ ( ( 𝐴 ⊆ 𝐵 ∧ 𝐴 ∈ V ) → 𝐴 ∈ 𝒫 𝐵 ) |
9 |
6 8
|
syldan |
⊢ ( ( 𝐴 ⊆ 𝐵 ∧ ( 𝐴 ∩ 𝐵 ) ∈ 𝑉 ) → 𝐴 ∈ 𝒫 𝐵 ) |
10 |
9
|
expcom |
⊢ ( ( 𝐴 ∩ 𝐵 ) ∈ 𝑉 → ( 𝐴 ⊆ 𝐵 → 𝐴 ∈ 𝒫 𝐵 ) ) |
11 |
1 10
|
impbid2 |
⊢ ( ( 𝐴 ∩ 𝐵 ) ∈ 𝑉 → ( 𝐴 ∈ 𝒫 𝐵 ↔ 𝐴 ⊆ 𝐵 ) ) |