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Metamath Proof Explorer

Theorem vuniex

Description: The union of a setvar is a set. (Contributed by BJ, 3-May-2021) (Revised by BJ, 6-Apr-2024)

Ref Expression
Assertion vuniex ∪ 𝑥 ∈ V

Proof

Step Hyp Ref Expression
1 uniex2 ⊢ ∃ 𝑦 𝑦 = ∪ 𝑥
2 1 issetri ⊢ ∪ 𝑥 ∈ V