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Metamath Proof Explorer

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