Theorem prnz

Description: A pair containing a set is not empty. (Contributed by NM, 9-Apr-1994)

	Ref	Expression
Hypothesis	prnz.1	$$⊢A\in \mathrm{V}$$
Assertion	prnz	$$⊢\left\{A,B\right\}\ne \varnothing$$

Proof

Step	Hyp	Ref	Expression
1		prnz.1	$$⊢A\in \mathrm{V}$$
2	1	prid1	$$⊢A\in \left\{A,B\right\}$$
3	2	ne0ii	$$⊢\left\{A,B\right\}\ne \varnothing$$