Description: Existence of a class of subsets. (Contributed by NM, 15-Jul-2006) (Proof shortened by Andrew Salmon, 25-Jul-2011)
Ref | Expression | ||
---|---|---|---|
Assertion | abssexg | ⊢ ( 𝐴 ∈ 𝑉 → { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ∈ V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | pwexg | ⊢ ( 𝐴 ∈ 𝑉 → 𝒫 𝐴 ∈ V ) | |
2 | df-pw | ⊢ 𝒫 𝐴 = { 𝑥 ∣ 𝑥 ⊆ 𝐴 } | |
3 | 2 | eleq1i | ⊢ ( 𝒫 𝐴 ∈ V ↔ { 𝑥 ∣ 𝑥 ⊆ 𝐴 } ∈ V ) |
4 | simpl | ⊢ ( ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) → 𝑥 ⊆ 𝐴 ) | |
5 | 4 | ss2abi | ⊢ { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ⊆ { 𝑥 ∣ 𝑥 ⊆ 𝐴 } |
6 | ssexg | ⊢ ( ( { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ⊆ { 𝑥 ∣ 𝑥 ⊆ 𝐴 } ∧ { 𝑥 ∣ 𝑥 ⊆ 𝐴 } ∈ V ) → { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ∈ V ) | |
7 | 5 6 | mpan | ⊢ ( { 𝑥 ∣ 𝑥 ⊆ 𝐴 } ∈ V → { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ∈ V ) |
8 | 3 7 | sylbi | ⊢ ( 𝒫 𝐴 ∈ V → { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ∈ V ) |
9 | 1 8 | syl | ⊢ ( 𝐴 ∈ 𝑉 → { 𝑥 ∣ ( 𝑥 ⊆ 𝐴 ∧ 𝜑 ) } ∈ V ) |