Theorem bj-tagn0

Description: The tagging of a class is nonempty. (Contributed by BJ, 6-Apr-2019)

	Ref	Expression
Assertion	bj-tagn0	$$⊢tagA\ne \varnothing$$

Proof

Step	Hyp	Ref	Expression
1		bj-0eltag	$$⊢\varnothing \in tagA$$
2	1	ne0ii	$$⊢tagA\ne \varnothing$$