Theorem nfcv

Description: If x is disjoint from A , then x is not free in A . (Contributed by Mario Carneiro, 11-Aug-2016)

	Ref	Expression
Assertion	nfcv	$$⊢\underset{\_}{Ⅎ}xA$$

Proof

Step	Hyp	Ref	Expression
1		nfv	$$⊢Ⅎxy\in A$$
2	1	nfci	$$⊢\underset{\_}{Ⅎ}xA$$