Metamath Proof Explorer


Theorem bj-sselpwuni

Description: Quantitative version of ssexg : a subset of an element of a class is an element of the powerclass of the union of that class. (Contributed by BJ, 6-Apr-2024)

Ref Expression
Assertion bj-sselpwuni ( ( 𝐴 ⊆ 𝐵 ∧ 𝐵 ∈ 𝑉 ) → 𝐴 ∈ 𝒫 ∪ 𝑉 )

Proof

Step Hyp Ref Expression
1 ssexg ⊢ ( ( 𝐴 ⊆ 𝐵 ∧ 𝐵 ∈ 𝑉 ) → 𝐴 ∈ V )
2 ssuni ⊢ ( ( 𝐴 ⊆ 𝐵 ∧ 𝐵 ∈ 𝑉 ) → 𝐴 ⊆ ∪ 𝑉 )
3 1 2 elpwd ⊢ ( ( 𝐴 ⊆ 𝐵 ∧ 𝐵 ∈ 𝑉 ) → 𝐴 ∈ 𝒫 ∪ 𝑉 )