Metamath Proof Explorer
Description: Power set axiom expressed in class notation, with the sethood
requirement as an antecedent. (Contributed by NM, 30-Oct-2003)
|
|
Ref |
Expression |
|
Assertion |
pwexg |
⊢ ( 𝐴 ∈ 𝑉 → 𝒫 𝐴 ∈ V ) |
Proof
Step |
Hyp |
Ref |
Expression |
1 |
|
pweq |
⊢ ( 𝑥 = 𝐴 → 𝒫 𝑥 = 𝒫 𝐴 ) |
2 |
1
|
eleq1d |
⊢ ( 𝑥 = 𝐴 → ( 𝒫 𝑥 ∈ V ↔ 𝒫 𝐴 ∈ V ) ) |
3 |
|
vpwex |
⊢ 𝒫 𝑥 ∈ V |
4 |
2 3
|
vtoclg |
⊢ ( 𝐴 ∈ 𝑉 → 𝒫 𝐴 ∈ V ) |