Theorem bnj105

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011) (New usage is discouraged.)

	Ref	Expression
Assertion	bnj105	$$⊢1_{𝑜}\in \mathrm{V}$$

Proof

Step	Hyp	Ref	Expression
1		df1o2	$$⊢1_{𝑜}=\left\{\varnothing \right\}$$
2		p0ex	$$⊢\left\{\varnothing \right\}\in \mathrm{V}$$
3	1 2	eqeltri	$$⊢1_{𝑜}\in \mathrm{V}$$