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Metamath Proof Explorer

Theorem vsnex

Description: A singleton built on a setvar is a set. (Contributed by BJ, 15-Jan-2025)

		Ref	Expression
	Assertion	vsnex	$⊢ \{x\} \in V$

Step	Hyp	Ref	Expression
1		dfsn2	$⊢ \{x\} = \{x, x\}$
2		zfpair2	$⊢ \{x, x\} \in V$
3	1 2	eqeltri	$⊢ \{x\} \in V$