Theorem nfcsb1v

Description: Bound-variable hypothesis builder for substitution into a class. (Contributed by NM, 17-Aug-2006) (Revised by Mario Carneiro, 12-Oct-2016)

	Ref	Expression
Assertion	nfcsb1v	$$⊢\underset{\_}{Ⅎ}x⦋A/x⦌B$$

Proof

Step	Hyp	Ref	Expression
1		nfcv	$$⊢\underset{\_}{Ⅎ}xA$$
2	1	nfcsb1	$$⊢\underset{\_}{Ⅎ}x⦋A/x⦌B$$