Theorem elexi

Description: If a class is a member of another class, then it is a set. Inference associated with elex . (Contributed by NM, 11-Jun-1994)

	Ref	Expression
Hypothesis	elexi.1	⊢ 𝐴 ∈ 𝐵
Assertion	elexi	⊢ 𝐴 ∈ V

Proof

Step	Hyp	Ref	Expression
1		elexi.1	⊢ 𝐴 ∈ 𝐵
2		elex	⊢ ( 𝐴 ∈ 𝐵 → 𝐴 ∈ V )
3	1 2	ax-mp	⊢ 𝐴 ∈ V