Theorem nfsbc1v

Description: Bound-variable hypothesis builder for class substitution. (Contributed by Mario Carneiro, 12-Oct-2016)

	Ref	Expression
Assertion	nfsbc1v	⊢ Ⅎ 𝑥 [ 𝐴 / 𝑥 ] 𝜑

Proof

Step	Hyp	Ref	Expression
1		nfcv	⊢ Ⅎ 𝑥 𝐴
2	1	nfsbc1	⊢ Ⅎ 𝑥 [ 𝐴 / 𝑥 ] 𝜑